Dictionary of Metal Terminology

A

Accordion Reed Steel

Hardened, tempered, polished and blued or yellow flat steel with dressed edges. Carbon content about 1.00%. Material has to possess good flatness, uniform hardness and high elasticity.

Acid-Brittleness

Brittleness resulting from pickling steel in acid; hydrogen, formed by the interaction between iron and acid, is partially absorbed by the metal, causing acid brittleness.

Acid-Process

A process of making steel, either Bessemer, open-hearth or electric, in which the furnace is lined with a siliceous refractory and for which low phosphorous pig iron is required as this element is not removed.

Acid-Steel

The term has no reference to the acidity of the steel. (See Acid Process.)

Age Hardening

The term as applied to soft or low carbon steels, relates to slow, gradual changes that take place in properties of steels after the final treatment. These changes, which bring about a condition of increased hardness, elastic limit, and tensile strength with a consequent loss in ductility, occur during the period in which the steel is at normal temperatures.

Aging

Spontaneous change in the physical properties of some metals, which occurs on standing, at atmospheric temperatures after final cold working or after a final heat treatment. Frequently synonymous with the term “Age-Hardening.”

Air Cooling

Cooling of the heated metal, intermediate in rapidity between slow furnace cooling and quenching, in which the metal is permitted to stand in the open air.

Air Hardening Steel

Alloy steel which may be hardened by cooling in air from a temperature above the transformation range. Such steels attain their martensitic structure without going through the quenching process. Additions of chromium, nickel, molybdenum and manganese are effective toward this end.

AISI Steels

Steels of the American Iron and Steel Institute. Common and alloy steels have been numbered in a system essentially the same as the SAE. The AISI system is more elaborate than the SAE in that all numbers are preceded by letters: “A” represents basic open-hearth alloy steel, “B” acid Bessemer carbon steel, “C” basic open-hearth carbon steel, “CB” either acid Bessemer or basic open-hearth carbon steel, “E” electric furnace alloy steel.

Alclad

The common name for a type of clad wrought aluminum products, such as sheet and wire, with coatings of high-purity aluminum or an aluminum alloy different from the core alloy in composition. The coatings are anodic to the core so they protect exposed areas on the core electrolytically during exposure to corrosive environments.

Allotropy

(See Polymorphism)

Alloy

(Met.) Metal prepared by adding other metals or non-metals to a basic metal to secure desirable properties.

Alloy Steel

Steel containing substantial quantities of elements other than carbon and the commonly-accepted limited amounts of manganese, sulfur, silicon, and phosphorous. Addition of such alloying elements is usually for the purpose of increased hardness, strength or chemical resistance. The metals most commonly used for forming alloy steels are: nickel, chromium, silicon, manganese, tungsten, molybdenum and vanadium. “Low Alloy” steels are usually considered to be those containing a total of less than 5% of such added constituents.

Alpha Brass

A copper–zinc alloy containing up to 38% of zinc. Used mainly for cold working.

Alpha Bronze

A copper–tin alloy consisting of the alpha solid solution of tin in copper. Commercial forms contain 4 or 5% of tin. This alloy is used in coinage, springs, turbine, blades, etc.

Alpha Iron

The polymorphic form of iron, stable below 1670°F. Has a body centered cubic lattice, and is magnetic up to 1410°F.

Aluminum

(Chemical symbol Al) Element No. 13 of the periodic system; Atomic weight 26.97; silvery white metal of valence 3; melting point 1220°F; boiling point approximately 4118°F; ductile and malleable; stable against normal atmospheric corrosion, but attacked by both acids and alkalis. Aluminum is used extensively in articles requiring lightness, corrosion resistance, electrical conductivity, etc. Its principal functions as an alloy in steel making are: (1) Deoxidizes efficiently (See Aluminum Killed Steel) (2) Restricts grain growth (by forming dispersed oxides or nitrides) (3) Alloying element in nitriding steel.

Aluminum Killed Steel

A steel where aluminum has been used as a deoxidizing agent. (See Killed Steel.)

Amorphous

Non–crystalline.

Annealing

A heating and cooling operation implying usually a relatively slow cooling. Annealing is a comprehensive term. The process of such a heat treatment may be: to remove stresses; to induce softness; to alter ductility; toughness; electrical, magnetic, or other physical properties; to refine the crystalline structure; to remove gases; to produce a definite micro-structure. In annealing, the temperature of the operation and the rate of cooling depend upon the material being heat treated and the purpose of the treatment.

Anodizing (Aluminum Anodic Oxide Coating)

A process of coating aluminum by anodic treatment resulting in a thin film of aluminum oxide of extreme hardness. A wide variety of dye-colored coatings are possible by impregnation in process.

Artificial Aging

An aging treatment above room temperature. (See Precipitation Heat Treatment and compare with Natural Aging)

A.S.T.M.

Abbreviation for American Society for Testing Material. An organization for issuing standard specifications on materials, including metals and alloys.

Austempering

A trade name for a patented heat treating process that consists of quenching a ferrous alloy from temperature above the transformation ranges, in a medium having a rate of heat abstraction sufficiently high to prevent the formation of high-temperature transformation products and in maintaining the alloy, until transformation is complete, at a temperature below that of pearlite formations and above that of martensite formation.

Austenite

Phase in certain steels, characterized as a solid solution, usually of carbon or iron carbide, in the gamma form of iron. Such steels are known as “austenitic.” Austenite is stable only above 1333°F in a plain carbon steel, but the presence of certain alloying elements, such as nickel and manganese, stabilizes the austenitic form, even at normal temperatures.

Austenitic Steel

Steel which, because of the presence of alloying elements such as manganese, nickel, chromium, etc., shows stability of Austenite at normal temperatures.

B

Bainite

A slender, needle-like (acicular) microstructure appearing in spring steel strip characterized by toughness and greater ductility than tempered Martensite. Bainite is a decomposition product of Austenite best developed at interrupted holding temperatures below those forming fine pearlite and above those giving Martensite.

Banded Structure

Appearance of a metal, under a microscope or viewed by the naked eye, on fractured or smoothed surfaces, with or without etching, showing parallel bands in the direction of rolling or working.

Band Saw Steel (Wood)

A hardened tempered bright polished high carbon cold rolled spring steel strip produced especially for use in the manufacture of band saws for sawing wood, non ferrous metals, and plastics. Usually carries some nickel and with a Rockwell value of approximately C40/45.

Bark

Surface of metal, under the oxide–scale layer, resulting from heating in an oxidizing environment. In the case of steel, such bark always suffers from decarburization.

Base Box

(See Tin Plate Base Box)

Basic Open Hearth

(See Open Hearth Process)

Basic Oxygen Process

A steel making process wherein oxygen of the highest purity is blown onto the surface of a bath of molten iron contained in a basic lined and ladle shaped vessel. The melting cycle duration is extremely short with quality comparable to Open Hearth Steel.

Basic Process

A steel making process either Bessemer, open hearth or electric, in which the furnace is lined with a basic refractory. A slag, rich in lime, being formed and phosphorous removed.

Basic Steel

(See Basic Process)

Bath Annealing

Immersion in a liquid bath (such as molten lead or fused salts) held at an assigned temperature. When a lead bath is used, the process is known as lead annealing.

Bauxite

The only commercial ore of aluminum, corresponding essentially to the formula Al2O3xh3O.

Beading

Raising a ridge on sheet metal.

Bend Test

Various tests used to determine the toughness and ductility of flat rolled metal sheet, strip or plate, in which the material is bent around its axis or around an outside radius. A complete test might specify such a bend to be both with and against the direction of grain. For testing, samples should be edge filed to remove burrs and any edgewise cracks resulting from slitting or shearing. If a vice is to be used then line the jaws with some soft metal or brass, so as to permit a free flow of the metal in the sample being tested.

Beryllium Copper

An alloy of copper and 2-3% beryllium with optionally fractional percentages of nickel or cobalt. Alloys of this series show remarkable age-hardening properties and an ultimate hardness of about 400 Brinell (Rockwell C43). Because of such hardness and good electrical conductivity, beryllium-copper is used in electrical switches, springs, etc.

Bessemer Process

A steel making process in which air is blown through the molten iron so that the impurities are thus removed by oxidation.

Billet

(See Bloom)

Binary Alloy

An alloy containing two elements, apart from minor impurities, as brass containing the two elements copper and zinc.

Black Annealing

A process of box annealing or pot annealing ferrous alloy sheet, strip or wire after hot working and pickling. (See Box Annealing)

Black Oil Tempered Spring Steel Strip

(Scaleless Blue.) A flat cold rolled usually .70/.80% medium high carbon spring steel strip, blue-black in color, which has been quenched in oil and drawn to desired hardness. While it looks and acts much like blue tempered spring steel and carries a Rockwell hardness of C44/47, it has not been polished and is lower in carbon content. Used for less exacting requirements than clock spring steel, such as snaps, lock springs, hold down springs, trap springs, etc. It will take a more severe bend before fracture than will clock spring, but it does not have the same degree of spring-back.

Black Plate

A light weight or a thin uncoated steel sheet or strip so called because of its dark oxide coloring prior to pickling. It is manufactured by two different processes. (1) From sheet bar on single stand sheet mills or sheer mills in tandem. This method is now almost obsolete. (2) On modern, high speed continuous tandem cold reduction mills from coiled hot rolled pickled wide strip into ribbon wound coils to finished gage. Sizes range from 12” to 32” in width, and in thicknesses from 55 lbs. to 275 lbs. base box weight. It is used either as is for stampings, or may be enameled or painted or tin or terne coated.

Blast Furnace

A vertical shaft type smelting furnace in which an air blast is used, usually hot, for producing pig iron. The furnace is continuous in operation using iron ore, coke, and limestone as raw materials which are charged at the top while the molten iron and slag are collected at the bottom and are tapped out at intervals.

Blast Box

(See Tin Plate Base Box)

Blister

A defect in metal produced by gas bubbles either on the surface or formed beneath the surface while the metal is hot or plastic. Very fine blisters are called “pin-head” or “pepper” blisters.

Bloom

(Slab, Billet, Sheet-Bar.) Semifinished products, hot rolled from ingots. The chief differences are in their cross sectional areas in ratio of width to thickness, and in their intended use.

Blooming-Mill

A mill used to reduce ingots to blooms, billets, slabs, sheet-bar etc. (See Semi-Finished Steel)

Blowhole

A cavity produced during the solidification of metal by evolved gas, which in failing to escape is held in pockets.

Blue Annealing

A process of softening ferrous alloys in the form of hot rolled sheet, by heating in the open furnace to a temperature within the transformation range and then cooling in air. The formation of bluish oxide on the surface is incidental.

Blue Brittleness

Reduced ductility occurring as a result of strain aging, when certain ferrous alloys are worked between 300° and 700°F. This phenomenon may be observed at the working temperature or subsequently at lower temperatures.

Blue Tempered Spring Steel Strips

(See Tempered Spring Steel Strip)

Bluing

(1) Sheets – A method of coating sheets with a thin, even film of bluish-black oxide, obtained by exposure to an atmosphere of dry steam or air, at a temperature of about 1000°F, generally this is done during box-annealing. (2) Bluing of tempered spring steel strip; an oxide film blue in color produced by low temperature heating.

Body-Centered

(Concerning space lattices.) Having the equivalent lattice points at the corners of the unit cell, and at its center; sometimes called centered or space-centered.

Bonderizing

The coating of steel with a film composed largely of zinc phosphate in order to develop better bonding surface for paint or lacquer.

Boron

(Chemical Symbol B)- Element No. 5 of the periodic system. Atomic weight 10.82. It is gray in color, ignites at about 1112°F. and burns with a brilliant green flame, but its melting point in a non-oxidizing atmosphere is about 4000°F. Boron is used in steel in minute quantities for one purpose only – to increase the hardenability as in case hardening and to increase strength and hardness penetration.

Bottle Top Mold

Ingot mold, with the top constricted; used in the manufacture of “capped steel,” the metal in the constriction being covered with a cap fitted into the bottleneck, which stops “rimming” action by trapping escaping gases.

Bow

(See Camber)

Box Annealing

A process of annealing a ferrous alloy in a suitable closed metal container, with or without packing materials, in order to minimize oxidation. The charge is usually heated slowly to a temperature below the transformation range, but sometimes above or within it, and is then cooled slowly. This process is also called “close annealing” or “pot annealing.” (See Black Annealing)

Brake

A piece of equipment used for bending sheet: also called a “bar folder.” If operated manually, it is called a “hand brake”; if power driven, it is called a “press brake.”

Bralé

A diamond penetrator, conical in shape, used with a Rockwell hardness tester for hard metals.

Brass (Cartridge)

Strip. 70% copper 30% zinc. This is one of the most widely used of the copper–zinc alloys; it is malleable and ductile; has excellent cold-working; poor hot working and poor machining properties; develops high tensile strength with cold-working. Temper is impaired by cold rolling and classified in hardness by the number of B & S Gages of rolling (reduction in thickness) from the previous annealing gage. Rated excellent for soft-soldering; good for silver alloy brazing or oxyacetylene welding and fair for resistance of carbon arc welding. Used for drawn cartridges, tubes, eyelet machine items, snap fasteners, etc.

Brass Shim

(See Shim)

Brass (Yellow)

Strip. 65% copper and 35% zinc. Known as “High Brass” or “Two to One Brass.” A copper–zinc alloy yellow in color. Formerly widely used but now largely supplanted by Cartridge Brass.

Brasses

Copper base alloys in which zinc is the principal added element. Brass is harder and stronger than either of its alloying elements copper or zinc; it is malleable and ductile; develops high tensile with cold-working and not heat treatable for purposes of hardness development.

Brazing

Joining metals by fusion of nonferrous alloys that have melting points above 800°F. but lower than those of the metals being joined. This may be accomplished by means of a torch (torch brazing), in a furnace (furnace brazing) or by dipping in a molten flux bath (dip or flux brazing). The filler metal is ordinarily in rod form in torch brazing; whereas in furnace and dip brazing the work material is first assembled and the filler metal may then be applied as wire, washers, clips, bands, or may be integrally bonded, as in brazing sheet.

Break Test

(For tempered steel) A method of testing hardened and tempered high carbon spring steel strip wherein the specimen is held and bent across the grain in a vice-like calibrated testing machine. Pressure is applied until the metal fractures at which point a reading is taken and compared with a standard chart of brake limitations for various thickness range. (See Bend Test)

Bridling

The cold working of dead soft annealed strip metal immediately prior to a forming, bending, or drawing operation. A process designed to prevent the formulation of Luder’s lines. Caution: Bridled metal should be used promptly and not permitted to (of itself) return to its pre-bridled condition.

Bright Annealed Wire

Steel wire bright drawn and annealed in controlled non-oxidizing atmosphere furnace.

Bright Annealing

A process of annealing usually carried out in a controlled furnace atmosphere so that surface oxidation is reduced to a minimum and the surface remains relatively bright.

Bright Basic Wire

Bright steel wire, slightly softer than Bright Bessemer Wire. Used for round head wood screws, bolts and rivets, electric welded chain, etc.

Bright Bessemer Wire

Stiff bright steel wire of hard drawn temper. Normally drawn to size without annealing. Used for nails, flat head wood screws, cheap springs, etc.

Bright Commercial Finish

(See Finishes)

Bright Dip

An acid solution into which articles are dipped to obtain a clean, bright surface.

Brinell Hardness (Test)

A common standard method of measuring the hardness of certain metals. The smooth surface of the metal is subjected to indentation by a hardened steel ball under pressure or load. The diameter of the resultant indentation, in the metal surface, is measured by a special microscope and the Brinell hardness value read from a chart or calculated formula.

Brittleness

A tendency to fracture without appreciable deformation.

Broaching

Multiple shaving, accomplished by pushing a tool with stepped cutting edges along the work, particularly through holes.

Bronze

Primarily an alloy of copper and tin but the name is now applied to other alloys not containing tin; e.g., aluminum, bronze, manganese bronze, and beryllium bronze. For varieties and uses of tin bronze see (Alpha Bronze and Phosphor Bronze).

Brown & Sharpe Gages (B & S)

A standard series of sizes arbitrarily indicated, as by numbers, to which the diameter of wire or thickness of sheet metal is usually made and which is used in the manufacture of brass, bronze, copper, copper-base alloys and aluminum. These gage numbers have a definite relationship to each other. By this system the decimal thickness is reduced by 50% every six gage numbers -while temper is expressed by the number of B S gage numbers as cold reduced in thickness from previous annealing. For each B & S gage number in thickness reduction, there is assigned a hardness value of ¼ hard. To illustrate: One number hard = ¼ hard, two numbers hard = ½ hard, etc.

Buckle

Alternate bulges or hollows recurring along the length of the product with the edges remaining relatively flat.

Burning

Heating a metal beyond the temperature limits allowable for the desired heat treatment, or beyond the point where serious oxidation or other detrimental action begins.

Burnt

A term applied to a metal permanently damaged by overheating.

Burr

A thin ridge or roughness left by a cutting operation such as in metal slitting, shearing, blanking or sawing. This is common to a No. 3 slit edge in the case of steel.

Butcher Saw Steel

A hardened, tempered, and bright polished high carbon spring steel strip (carbon content a bit higher than in wood band saw quality) with a Rockwell value of approximately C47/49.

Butt Welding

Joining two edges or ends by placing one against the other and welding them.

C

Cake

A copper ingot rectangular in cross section intended for rolling.

Camber or Bow

Edgewise curvature. A lateral departure of a side edge of sheet or strip metal from a straight line.

Camera Shutter Steel

Hardened, tempered and bright polished extra flat and extra precision rolled. Carbon content 1.25, Chromium .15.

Capped Steel

(See Bottle Top Mold)

Carbide

A compound of carbon with one or more metallic elements.

Carbon

(Chemical symbol C) – Element No. 6 of the periodic system; atomic weight 12.01; has three allotropic modifications, all non-metallic. Carbon is present in practically all ferrous alloys, and has tremendous effect on the properties of the resultant metal. Carbon is also an essential compound of the cemented carbides. Its metallurgical use, in the form of coke, for reduction of oxides, is very extensive.

Carbon Free

Metals and alloys which are practically free from carbon.

Carbon Range

In steel specifications, the carbon range is the difference between the minimum and maximum amount of carbon acceptable.

Carbon Steel

Common or ordinary steel as contrasted with special or alloy steels, which contain other alloying metals in addition to the usual constituents of steel in their common percentages.

Carburizing

(Cementation) Adding carbon to the surface of iron-base alloys by absorption through heating the metal at a temperature below its melting point in contact with carbonaceous solids, liquids or gasses. The oldest method of case hardening.

Case Hardening

Carburizing and subsequently hardening by suitable heat-treatment, all or part of the surface portions of a piece of iron-base alloy.

Cast

(1) A term indicating in the annealed state as “Cast Spring Steel Wire.” (2) In reference to Bright or Polished Strip Steel or Wire, the word cast implies discoloration as a shadow. (3) A term implying a lack of straightness as in a coil set.

Cast Steel

Any object made by pouring molten steel into molds.

Cementite

A compound of iron and carbon known as “Iron Carbide,” which has the approximate chemical formula Fe3C containing 6.69% of carbon. Hard and brittle, it is the hard constituents of cast iron, and the normal form in which carbon is present in steel. It is magnetizable, but not as readily as ferrite.

Charcoal Tin Plate

Tin Plate with a relatively heavy coating of tin (higher than the “Coke Tin Plate” grades).

Chatter Marks

(Defect) – Parallel indentations or marks appearing at right angles to edge of strip forming a pattern at close and regular intervals, caused by roll vibrations.

Chipping

A method for removing seams and surface defects with chisel or gouge so that such defects will not be worked into the finished product. Chipping is often employed to remove metal that is excessive but not defective. Removal of defects by gas cutting is known as “deseaming” or “scarfing.”

Chromium

(Chemical symbol Cr.) – Element No. 24 of the periodic system; atomic weight 52.01. It is of bright silvery color, relatively hard. It is strongly resistant to atmospheric and other oxidation. It is of great value in the manufacture of Stainless Steel as an iron-base alloy. Chromium plating has also become a large outlet for the metal. Its principal functions as an alloy in steel making are: (1) increases resistance to corrosion and oxidation (2) increases hardenability (3) adds some strength at high temperatures (4) resists abrasions and wear (with high carbon).

Chromium-Nickel Steel

Steel usually made by the electric furnace process in which chromium and nickel participate as alloying elements. The stainless steel of 18% chromium and 8% nickel are the better known of the chromium–nickel types.

Cigarette Knife Steel

Hardened, tempered and bright polished. 1.25 Carbon content – Chromium .15. Accurate flatness necessary and a high hardness with Rockwell C 51 to 53. Usually sizes are 4 ¾” wide and 6” wide x .004 to .010.

Cladding

A process for covering one metal with another. Usually the surfaces of fairly thick slabs of two metals are brought carefully into contact and are then subjected to co-rolling so that a clad composition results. In some instances a thick electroplate may be deposited before rolling.

Clad Metal

A composite metal containing two or three layers that have been bonded together. The bonding may have been accomplished by co-rolling, welding, heavy chemical deposition or heavy electroplating.

Cluster Mill

A rolling mill where each of the two working rolls of small diameter is supported by two or more back-up rolls.

Cobalt

(Chemical symbol Co.) – Element No. 27 of the periodic system; atomic weight 58.94. A gray magnetic metal of medium hardness; it resists corrosion like nickel, which it resembles closely; melting point 2696°F.; boiling point about 5250°F.; specific gravity 8.9. It is used as the matrix metal in most cemented carbides and is occasionally electroplated instead of nickel, the sulfate being used as electrolyte. Its principal function as an alloy in tool steel is that it contributes to red hardness by hardening ferrite.

Coil Set or Longitudinal Curl

A lengthwise curve or set found in coiled strip metals following its coil pattern. A departure from longitudinal flatness. It can be removed by roller or stretcher leveling from metals in the softer temper ranges.

Coils

Coiled flat sheet or strip metal – usually in one continuous piece or length.

Coining

A process of impressing images or characters of the die and punch onto a plane metal surface.

Coke Plate

(Hot Dipped Tin Plate) Standard tin plate, with the lightest commercial tin coat, used for food containers, oil canning, etc. A higher grade is the best cokes, with special cokes representing the best of the coke tin variety. For high qualities and heavier coatings, see (Charcoal Tin Plate).

Coil Breaks

Creases or ridges appearing in sheets as parallel lines transverse to the direction of rolling and generally extending across the width of the sheet.

Coil Weld

A joint between two lengths of metal within a coil – which is not always visible in the cold reduced product.

Cold Reduced Strip

Metal strip, made from hot-rolled strip, by rolling on cold-reduction mills.

Cold Reduction

Reduction of metal size, usually by rolling or drawing particularly thickness, while the metal is maintained at room temperature or below the recrystallization temperature of the metal.

Cold Rolled Finish

Finish obtained by cold rolling plain pickled sheet or strip with a lubricant resulting in a relatively smooth appearance.

Cold Rolling

Rolling metal at a temperature below the softening point of the metal to create strain hardening (work-hardening). Same as cold reduction, except that the working method is limited to rolling. Cold rolling changes the mechanical properties of strip and produces certain useful combinations of hardness, strength, stiffness, ductility and other characteristics known as tempers.

Cold Short

The characteristics of metals that are brittle at ordinary or low temperatures.

Cold Shut

A defect produced during casting, causing an area in the metal where two portions of the metal in either a molten or plastic condition have come together but have failed to unite, fuse, or, blend into a solid mass. (See Lamination)

Cold Working

Plastic deformation, such as rolling, hammering, drawing, etc., at a temperature sufficiently low to create strain hardening (work-hardening). Commonly, the term refers to such deformation at normal temperatures.

Columbium

(Chemical Symbol Cb) – Element No. 41 of the periodic system. Atomic weight 92.91. It is steel gray in color and brilliant luster. Specific gravity 8.57. Melting point at about 4379°F. It is used mainly in the production of stabilized austenitic chromium–nickel steels, also to reduce the air-hardening characteristics in plain chromium steels of the corrosion resistant type.

Commercial Bronze

A copper–zinc alloy (brass) containing 90% copper and 10% zinc; used for screws, wire, hardware, etc. Although termed “commercial-bronze” it contains no tin. It is somewhat stronger than copper and has equal or better ductility.

Commercial Finish

(See Finishes)

Commercial Quality Steel Sheet

Normally to a ladle analysis of carbon limited at 0.15 max. A Standard Quality Carbon Steel Sheet.

Continuous Casting

A casting technique in which the ingot is continuously solidified while it is being poured, and the length is not determined by mold dimensions.

Continuous Furnace

Furnace, in which the material being heated moves steadily through the furnace.

Continuous Pickling

Passing sheet or strip metal continuously through a series of pickling and washing tanks.

Continuous Strip Mill

A series of synchronized rolling mill stands in which coiled flat rolled metal entering the first pass (or stand) moves in a straight line and is continuously reduced in thickness (not width) at each subsequent pass. The finished strip is recoiled upon leaving the final or finishing pass.

Controlled Atmosphere Furnaces

A furnace used for bright annealing into which specially prepared gases are introduced for the purposes of maintaining a neutral atmosphere so that no oxidizing reaction between metal and atmosphere takes place.

Converter

A furnace in which air is blown through the molten bath of crude metal or matte for the purpose of oxidizing impurities.

Cooling Stresses

Stresses developed by uneven contraction or external constraint of metal during cooling; also those stresses resulting from localized plastic deformation during cooling and retained.

Copper

(Chemical symbol Cu) – Element No. 29 of the periodic system, atomic weight 63.57. A characteristically reddish metal of bright luster, highly malleable and ductile and having high electrical and heat conductivity; melting point 1981°F.; boiling point 4237°F.; specific gravity 8.94. Universally used in the pure state as sheet, tube, rod and wire and also as alloyed by other elements (See Brass and Bronze), as an alloy with other metals.

Core Wound Flat Wire

(See Oscillated Wound Coils)

Corrosion

Gradual chemical or electrochemical attack on a metal by atmosphere, moisture or other agents.

Corrosion Embrittlement

The embrittlement caused in certain alloys by exposure to a corrosive environment. Such material is usually susceptible to the intergranular type of corrosion attack.

Corrugated

As a defect. Alternate ridges and furrows. A series of deep short waves.

Creep

The flow or plastic deformation of metals held for long periods of time at stresses lower than the normal yield strength. The effect is particularly important if the temperature of stressing is above the recrystallization temperature of the metal.

Critical Points

Temperatures at which internal changes or transformations take place within a metal either on a rising or falling temperature.

Critical Range

A temperature range in which an internal change takes place within a metal. Also termed Transformation Range.

Crop

The defective ends of a rolled or forged product which are cut off and discarded.

Cross Break

(See Luders Lines) This term also applies to transverse ribs or ripples.

Cross Direction

(In rolled or drawn metal) The direction parallel to the axis of the rolls during rolling. The direction at right angles to the direction of rolling or drawing.

Cross Rolling

Rolling at an angle to the long dimension of the metal; usually done to increase width.

Crown or Heavy Center

Increased thickness in the center of metal sheet or strip as compared with thickness at the edge.

Crucible

A ceramic pot or receptacle made of graphite and clay, or other refractory materials, and used in the melting of metal. The term is sometimes applied to pots made of cast iron, cast steel or wrought steel.

Crystal

(1) A physically homogeneous solid, in which the atoms, ions, or molecules are arranged in a three-dimensional repetitive pattern. (2) A coherent piece of matter, all parts of which have the same anisotropic arrangement of atoms; in metals, usually synonymous with “grain” and “crystallite.”

Crystalline

Composed of crystals.

Crystallization

The formation of crystals by the atoms assuming definite positions in a crystal lattice. This is what happens when a liquid metal solidifies. (Fatigue, the failure of metals under repeated stresses, is sometimes falsely attributed to crystallization.)

Cube-Centered

Metallography – (Concerning space lattices) – Body-centered cubic. Refers to crystal structure.

Cup Fracture

A type of fracture in a tensile test specimen which looks like a cup having the exterior portion extended with the interior slightly depressed.

Cup Test

(See Olsen Ductility Test)

Cyaniding

Surface hardening of an iron-base alloy article or portion of it by heating at a suitable temperature in contact with a cyanide salt, followed by quenching.

D

Dead Flat

Perfectly flat. As pertaining to sheet, strip or plate. (See Stretcher Leveling)

Dead Soft Annealing

Heating metal to above the critical range and appropriately cooling to develop the greatest possible commercial softness or ductility.

Dead Soft Steel

Steel, normally made in the basic open-hearth furnace or by the basic oxygen process with carbon less than 0.10% and manganese in the 0.20-0.50% range, completely annealed.

Dead Soft Temper

(No. 5 TEMPER) – Condition of maximum softness commercially attainable in wire, strip, or sheet metal in the annealed state.

Deburring

A method whereby the raw slit edge of metal is removed by rolling or filing.

Decarburization

Removal of carbon from the outer surface of iron or steel, usually by heating in an oxidizing or reducing atmosphere. Water vapor, oxygen and carbon dioxide are strong decarburizers. Reheating with adhering scale is also strongly decarburizing in action.

Deep Drawing

The process of cold working or drawing sheet or strip metal blanks by means of dies on a press into shames which are usually more or less cup-like in character involving considerable plastic deformation of the metal. Deep-drawing quality sheet or strip steel, ordered or sold on the basis of suitability for deep-drawing.

Degassing Process

(In steel making) – Removing gases from the molten metal by means of a vacuum process in combination with mechanical action.

Delta Iron

Allotropic modification of iron, stable above 2552°F. to melting point. It is of body-centered cubic crystal structure.

Deoxidizing

Removal of oxygen. In steel sheet, strip, and wire technology, the term refers to heat treatment in a reducing atmosphere, to lessen the amount of scale. (See Controlled Atmosphere Furnaces)

Die-Lines

Lines of markings caused on drawn or extruded products by minor imperfections in the surface of the die.

Die Sinking

Forming or machining a depressed pattern in a die.

Dish

A concave surface departing from a straight line edge to edge. Indicates transverse or across the width.

Doctor Blade Steel Strip

A hardened and tempered spring steel strip, usually blued, produced from approximately .85 carbon cold rolled spring steel strip specially selected for straightness and good edges. Sometimes hand straightened or straightened by grinding and cut to desired lengths. This product is used in the printing trade as a blade to uniformly remove excess ink (“dope”) from the rolls; hence its name.

Drawing Back

Reheated after hardening to a temperature below the critical for the purpose of changing the hardness of the steel. (See Tempering)

Drill Rod

A term given to an annealed and polished high carbon tool steel rod usually round and centerless ground. The sizes range in round stock from .013 to 1 ½” diameter. Commercial qualities embrace water and oil hardening grades. A less popular but nevertheless standard grade is a non-deforming quality. Drill Rods are used principally by machinists and tool and die makers for punches, drills, taps, dowel pins, screw machine parts, small tools, etc.

Dry Rolled Finish

Finish obtained by cold rolling on polished rolls without the use of any coolant or metal lubricant, material previously plain pickled, giving a burnished appearance.

Ductility

The property of metals that enables them to be mechanically deformed when cold, without fracture. In steel, ductility is usually measured by elongation and reduction of area as determined in a tensile test.

Duralumin

The trade name applied to the first aluminum–copper–magnesium type of age-hardenable alloy (17S), which contains nominally 4% Cu, ½ % Mg. The term is sometimes used to include the class of wrought aluminum–copper–magnesium alloys that harden during aging at room temperature.

E

Earing

Wavy projections formed at the opera end of a cup or shell in the course of deep drawing because of differences in directional properties. Also termed scallop. (See Non-Scalloping Quality Strip Steel)

Edges

Many types of edges can be produced in the manufacture of flat rolled metal products. Over the years the following types of edges have become recognized as standard in their respective fields.

Copper Base Alloys
Slit, Slit and Edge Rolled, Sheared, Sawed, Machined or Drawn,

Sheet Steels or Aluminum Sheet
Mill Edge, Slit Edge or Sheared Edge.

Strip Steels and Stainless Strip
No. 1 Edge – A smooth, uniform, round or square edge, either slit or filed or slit and edge rolled as specified, width tolerance +/-.005”.

No. 2 Edge – A natural round mill edge carried through from the hot rolled band. Has not been slit, filed, or edge rolled. Tolerances not closer than hot-rolled strip limits.

No. 3 Edge – Square, produced by slitting only. Not filed. Width tolerance close.

No. 4 Edge – A round edge produced by edge rolling either from a natural mill edge or from slit edge strip. Not as perfect as No. 1 edge. Width tolerances liberal.

No. 5 Edge – An approximately square edge produced by slitting and filing or slitting and rolling to remove burr.

No. 6 Edge – A square edge produced by square edge rolling, generally from square edge hot-rolled occasionally from slit strip. Width tolerances and finish not as exacting as No. 1 edge.

Edge Filing

A method whereby the raw or slit edges of strip metal are passed or drawn one or more times against a series of files, mounted at various angles. This method may be used for deburring only or filing to a specific contour including a completely rounded edge.

Edge Strain or Edge Breaks

Creases extending in from the edge of the temper rolled sheet.

Edgewise Curvature

(See Camber)

Edging

The dressing of metal strip edges by rolling, filing or drawing.

Elastic Limit

Maximum stress that a material will stand before permanent deformation occurs.

Electric Furnace Steel

Steel made in any furnace where heat is generated electrically, almost always by arc. Because of relatively high cost, only tool steels and other high-value steels are made by the electric furnace process.

Electrocleaning

(Electrolytic Brightening) – An anodic treatment. A cleaning, polishing, or oxidizing treatment in which the specimen or work is made the anode in a suitable electrolyte; an inert metal is used as cathode and a potential is applied.

Electro-Galvanizing

Galvanizing by electrodeposition of zinc on steel.

Electrolytic Polishing

(See Electrocleaning)

Electrolytic Tin Plate

Black Plate that has been tin plated on both sides with commercially pure tin by electrodeposition. (See Tin Plating)

Electroplating

The production of a thin coating of one metal on another by electrodeposition. It is very extensively used in industry and is continuing to enlarge its useful functions. Various plated metals and combinations thereof are being used for different purpose to illustrate:

1. Decoration and protection against corrosion – copper, nickel and chromium.
2. Protection against corrosion – cadmium or zinc
3. Protection against wear – chromium
4. Build-up of a part or parts undersize – chromium or nickel
5. Plate for rubber adhesion – brass
6. Protection against carburization and for brazing operations – copper and nickel

Elongation

Increase in length which occurs before a metal is fractured, when subjected to stress. This is usually expressed as a percentage of the original length and is a measure of the ductility of the metal.

Embossing

Raising or indenting a design in relief on a sheet or strip of metal by passing between rolls of desired pattern. (See Patterned or Embossed Sheet)

Endurance Limit

Maximum alternating stress, which a given material will withstand for an indefinite number of times, without causing fatigue failure.

Erichsen Test

Similar to the Olsen Test. Readings are in millimeters.

Etching

In metallography, the process of revealing structural details by the preferential attack of reagents on a metal surface.

Eutectoid Steel

Steel representing the eutectoid composition of the iron carbon system, with about 0.80% to 0.83% carbon, the eutectoid temperature being about 1333°F. Such steel in the annealed condition consists exclusively of pearlite. Steels with less than this quota of carbon are known as hypo-eutectoid and contain free ferrite in addition to the pearlite. When more carbon is present, the steel is known as hyper-eutectoid and contains free cementite. The presence of certain elements, such as nickel or chromium, lowers the eutectoid carbon content.

Expander Steel

Hardened and tempered, blue polished. Carbon content about 1.00, Chromium .17. Used for the expanders in oil piston rings. Hardness 30 N 70 to 73. Range of sizes run for grooves 3/32” to ¼” wide with the steel approximately .003% less than the grooves and thickness from .012 to .020”.

Extensometer

An apparatus for indicating the deformation of metal while it is subjected to stress.

Extensometer Test

The measurement of deformation during stressing in the elastic range, permitting determination of elastic properties such as proportional limit, proof stress, yield strength by the offset method and so forth. Requires the use of special testing equipment and testing procedures such as the use of an extensometer or the plotting of a stress–strain diagram.

Extra Hard Temper

In brass mill terminology, Extra Hard is six B & S numbers hard or 50.15% reduction from the previous annealing or soft stage.

Extra Spring Temper

In brass mill terminology, Extra Spring is ten numbers hard or 68.55% reduction in thickness from the previous annealing or soft stage.

Extrusion

Shaping metal into a chosen continuous form by forcing it through a die of appropriate shape.

F

Face Centered

(Concerning cubic space lattices) – Having equivalent points at the corners of the unit cell and at the centers of its six faces. A face-centered cubic space lattice is characteristic of one of the close-packed arrangements of equal hard spheres.

Fatigue

The phenomenon leading to fracture under repeated or fluctuating stress. Fatigue fractures are progressive beginning as minute cracks and grow under the action of fluctuating stress.

Ferritic Stainless Steel

Has a body centered cubic (BCC) structure. These alloys are the chromium stainless steels containing low carbon levels. They are hardenable primarily by cold working, although some will harden slightly by heat treating. Ferritic stainless steels work harden much slower than austentitic stainless steels.

Ferroalloy

An alloy of iron with a sufficient amount of some element or elements such as manganese, chromium or vanadium for use as a means in adding these elements into molten steel.

Ferro-Manganese

An alloy of iron and manganese (80% manganese) used in making additions of manganese to steel or cast–iron.

Ferrous

Related to iron (derived from the Latin ferrum.) Ferrous alloys are, therefore, iron base alloys.

Fiber or Fibre

Direction in which metals have been caused to flow, as by rolling, with microscopic evidence in the form of fibrous appearance in the direction of flow.

Fiber Stress

Unit stress which exists at any given point in a structural element subjected to load; given as load per unit area.

Filed Edges

Finished edges, the final contours of which are produced by drawing the strip over a series of small steel files. This is the usual and accepted method of dressing the edges of annealed spring steel strip after slitting in cases where edgewise slitting cracks are objectionable or slitting burr is to be removed.

Finished Steel

Steel that is ready for the market without further work or treatment. Blooms, billets, slabs, sheet bars and wire rods are termed “semi-finished”.

Finishes

The surface appearance of the various metals after final treatment such as rolling, etc. Over the years the following finishes have become recognized as standard in their respective fields.

Aluminum Sheet
(A) Commercially Bright.
(B) Bright one side.
(C) Bright both sides.
(D) Embossed Sheets – Produced by using embossed rolls.

Black Plate
(A) Dull finish without luster produced by use of roughened rolls.
(B) Bright finish – a luster finish produced by use of rolls having a moderately smooth surface.

Cold Rolled Steel Sheets
(A) Commercial Finish – A dull satin surface texture produced by roughened rolls.
(B) Commercial Bright Finish – Bright in appearance with a texture between luster and a very fine matte finish.
(C) Luster Finish – Produced by use of ground and polished rolls. (Note: This is not a number 3 finish.)

Cold Rolled Strip Steels
No. 1 Finish – A dull finish produced without luster by rolling on roughened rolls.
No. 2 Finish – A regular bright finish produced by rolling on moderately bright rolls.
No. 3 Finish – Best Bright Finish. A lustrous or high gloss finish produced by rolling on highly polished rolls. Also referred to as “Mirror Finish”.

Copper Base Alloys
Acid Dipped – Dry rolled finished, resulting in a burnished appearance and retaining the color obtained by dipping (True Metal Color).
Bright Dipped Finish – Finish resulting from an acid dip.
Buffed or Polished Surface – A finish obtained by buffing, resulting in a high gloss or polished finish.
Cold Rolled Finish – A relatively smooth finish obtained by cold rolling plain pickled strip with a lubricant.
Dry Rolled Finish – A burnished finish resulting from dry cold rolling by use of polished rolls without any metal lubricant.
Hot Rolled Finish – A dark relatively rough oxidized finish resulting from rolling the metal while hot. May subsequently be pickled or bright dipped but the rough surface remains.
Stretched Brushed Finish (Satin Finish) – Obtained by mechanically brushing with wire brushes or by buffing.

Flat Wire
No. 2 Finish – A regular bright finish.
No. 3 Finish – Best Bright High Gloss finish produced by use of polished rolls. Or by special buffing – this is a negotiated finish.

Stainless Cold Rolled Sheet and Strip
No. 1 Finish – C.R. Annealed and pickled, appearance varies from dull gray matte finish to a fairly reflective surface.
No. 2B Finish – Same as No. 1 Finish followed by a final light cold rolled pass generally on highly polished rolls.
No. 2D Finish – A dull cold rolled finish produced by cold rolling on dull rolls.

Stainless C.R. Sheet – Polished Finishes
No. 3 Finish – Intermediate polished finish.
No. 4 Finish – Ground and polished finish.
No. 6 Finish – Ground, polished and Tampico brushed.
No. 7 Finish – Ground and high luster polished.
No. 8 Finish – Ground and polished to mirror finish.

Tempered and Untempered Cold Rolled Carbon Spring Steel Strip
(A) Black Oil Tempered.
(B) Scaleless Tempered.
(C) Bright Tempered.
(D) Tempered and Polished.
(E) Tempered, Polished and Colored (Blue or Straw).

Tin Plate
(A) Bright Hot Dipped Finish.
(B) Electro Matte Dull Finish.
(C) Electro Bright Reflow Finish – produced by in-the-line thermal treatment following electrodeposition.

Finishing Temperature

Temperature of final hot-working of a metal.

Flame Annealing

A process of softening a metal by the application of heat from a high temperature flame.

Flame Hardening

A process of hardening a ferrous alloy by heating it above the transformation range by means of a high-temperature flame, and then cooling as required.

Flapper Valve Steel

An extremely flat, very smooth, very accurate to gage, polished, hardened and tempered spring steel produced from approximately 1.15% carbon. The name is derived from its common and principal usage.

Flattening

(See Roller and Stretcher Leveling)

Flat Latch Needle Steel

Supplied cold rolled and annealed. Carbon content .85. Supplied both in coil and flat length. Used to make flat latch needles which are used in the manufacture of knitted goods.

Flat Wire

A flat cold rolled, prepared edge section up to ¼” wide, rectangular in shape. Generally produced from hot rolled rods or specially prepared round wire by one or more cold rolling operations, primarily for the purpose of obtaining the size and section desired. May also be produced by slitting cold rolled flat metal to desired width followed by edge dressing.

Flowlines

Always visible to a greater or less degree when a longitudinal section has been subjected to macro etching, indicating the direction of work or rolling.

Flow Stress

The shear stress required to cause plastic deformation of solid metals.

Fluting

Kinking or breakage due to curving of metal strip on a radius so small, with relation to thickness, as to stretch the outer surface above its elastic limit. Not to be confused with the specific product, Fluted Tubes.

Foil

Metal in any width but no more than about 0.005” thick.

Folds

Defects caused in metal by continued fabrication of overlapping surfaces.

Fracture

Surface appearance of metals when broken.

Fracture Test

Nicking and breaking a bar by means of sudden impact, to enable macroscopic study of the fracture.

Friction Gouges or Scratches

A series of relatively short surface scratches variable in form and severity. (See Galling)

Full Annealing

Used principally on iron and steel, means heating the metal to about 100°F above the critical temperature range, followed by “soaking” at this point and slow cooling below the critical temperature.

Full Finish Plate

Steel sheet or strip reduced either hot or cold, cleaned, annealed, and then cold-rolled to a bright finish.

Full Hard Temper

(A) No. 1 Temper – In low carbon sheet or strip steel, stiff and springy, not suitable for bending in any direction. It is the hardest temper obtainable by hard cold rolling.
(B) In Stainless Steel Strip, tempers are based on minimum tensile or yield strength. For Chromium-Nickel grades Full Hard temper is 185,000 TS, 140,000 YS Min. Term also used in connection with copper base alloys and considered synonymous with Hard Temper.

G

Gages

(Metal) – Mfrs. standard numbering systems indicating decimal thickness or diameters.

Galling

The damaging of one or both metallic surfaces by removal of particles from localized areas due to seizure curing sliding friction.

Galvanizing

Coating steel with zinc and tin (principally zinc) for rust proofing purposes. Formerly for the purpose of galvanizing, cut length steel sheets were passed singly through a bath of the molten metal. Today’s galvanizing processing method consists of uncoiling and passing the continuous length of successive coils either through a molten bath of the metal termed Hot Dipped Galvanizing or by continuously zinc coating the uncoiled sheet electrolytically – termed Electro-Galvanizing.

Gamma Iron

The form of iron stable between 1670°F., and characterized by a face-centered cubic crystal structure.

Gilding Metal

A copper–zinc alloy containing 95% copper and 5% zinc. While similar to deoxidized copper in physical properties, it is somewhat stronger and very ductile. It has thermal and electrical conductivity slightly better than half that of electrolytic copper and corrosion resistance comparable to copper.

Grain

A solid polyhedral (or many sided crystal) consisting of groups of atoms bound together in a regular geometric pattern. In mill practice grains are usually studied only as they appear in one plane. (1) Direction of: Refers to grain fiber following the direction of rolling and parallel to edges of strip or sheets. (2) To bend across the grain is to bend at right angles to the direction of rolling. (3) To bend with the grain is to bend parallel to the direction of rolling. In steel, the ductility in the direction of rolling is almost twice that at right angles to the direction of rolling.

Grain Boundary

Bounding surface between crystals. When alloys yield new phases (as in cooling), grain boundaries are the preferred location for the appearance of the new phase. Certain deteriorations, such as season cracking and caustic embrittlement, occur almost exclusively at grain boundaries.

Grain Growth

An increase in metallic crystal size as annealing temperature is raised; growth occurs by invasion of crystal areas by other crystals.

Grains

Individual crystals in metals.

Grain Size

Average diameter of grains in the metal under consideration, or alternatively, the number of grains per unit area. Since increase in grain size is paralleled by lower ductility and impact resistance, the question of general grain size is of great significance. The addition of certain metals affects grain size, for examplevanadium and aluminum tend to give steel a fine grain. The ASTM has set up a grain size standard for steels, and the McQuaid-Ehn Test has been developed as a method of measurement.

Granulated

A coarse grain or pebbly surface condition which becomes evident during drawing. (See Orange Peel)

Granulation

The formation of grains immediately upon solidification.

Graphitizing

A heating and cooling process by which the combined carbon in cast iron or steel is transformed, wholly or partly, to graphitic or free carbon.

Ground Flat Stock

Annealed and preground (to close tolerances) tool steel flats in standard sizes ready for tool room use. These are three common grades; water hardening, oil hardening and air hardening quality.

Guide

Device for holding the metal in the proper position, during rolling, or slitting.

Guide Scratch

(Defect) – Scratches or marks appearing parallel to edges of cold rolled strip caused by scale or other articles which have become imbedded in or have adhered to the rolling mill guide. Also applies to similar scratches appearing as a result of slitting.

H

Half Hard Temper

(A) No. 2 Temper. In low carbon cold-rolled strip steel, produced by cold rolling to a hardness next to but somewhat softer than full hard temper. (B) In brass Stainless Steel Strip, tempers are based on minimum tensile or yield strength. For Chromium–Nickel grades Half-Hard Temper 150,000 TS., 110,000 YS. Min.

Hard Drawing

Drawing metal wire through a die to reduce cross section and increase tensile strength.

Hard Drawn

Wire or tubing drawn to high tensile strength by a high degree of cold work.

Hard Drawn Spring Steel Wire

A medium high carbon cold drawn spring steel wire. Used principally for cold springs.

Hardenability

The ability of a metal, usually steel, to harden in depth as distinguished from the terms “hardness.”

Hardened and Tempered Spring Steel Strip

A medium or high carbon quality steel strip which has been subjected to the sequence of heating, quenching and tempering.

Hardening

Any process which increases the hardness of a metal. Usually heating and quenching certain iron base alloys from a temperature either within or above the critical temperature range.

Hardness

Degree to which a metal will resist cutting, abrasion, penetration, bending and stretching. The indicated hardness of metals will differ somewhat with the specific apparatus measuring hardness. (See Brinell Hardness, Rockwell Hardness, Vickers Hardness, Scleroscope Hardness) Tensile Strength also is an indication of hardness.

Hard Temper

(A) For Steel see Full Hard Temper. (B) In brass mill terminology. Hard Temper is four B & S numbers hard or 37.1 % reduction.

Heat of Steel

The product of a single melting operation in a furnace, starting with the charging of raw materials and ending with the tapping of molten metal and consequently identical in its characteristics.

Heat Treatment

Altering the properties of a metal by subjecting it to a sequence of temperature changes, time of retention at specific temperature and rate of cooling therefore being as important as the temperature itself. Heat treatment usually markedly affects strength, hardness, ductility, malleability, and similar properties of both metals and their alloys.

High Brass

65% – A copper–zinc alloy containing 35% zinc. Possesses high tensile strength and is used for springs, screws, rivets, etc.

Hooke’s Law

Stress is proportional to strain in the elastic range. The value of the stress at which a material ceases to obey Hooke’s law is known as the elastic limit.

Hot Dip

In steel mill practice, a process whereby ferrous alloy base metals are dipped into molten metal, usually zinc, tin or terne, for the purpose of fixing a rust resistant coating.

Hot Short

Brittleness in hot metal.

Hot Top

(See Sinkhead)

Hot Working

Plastic deformation of metal at a temperature sufficiently high not to create strain hardening. The lower limit of temperature for this process is the recrystallization temperature.

Hydrogen Embrittlement

(1) Brittleness of metal, resulting from the occlusion of hydrogen (usually as a by-product of pickling or by co-deposition in electroplating). (2) A condition of low ductility resulting from hydrogen absorption and internal pressure developed subsequently. Electrolytic copper exhibits similar results when exposed to reducing atmosphere at elevated temperature.

Hypereutectoid Steel

A steel having more than the eutectoid percentage of carbon. (See Eutectoid Steel)

Hypoeutectoid Steel

Steel with less than eutectoid percentage of carbon. (See Eutectoid Steel)

I

Impact Test

Test designed to determine, the resistance of metal to breakage by impact, usually by concentrating the applied stress to a notched specimen.

Inclusion

Particles of impurities (usually oxides, sulfides, silicates, etc.) that are held mechanically or are formed during the solidification or by subsequent reaction within the solid metal.

Indentation Hardness

The resistance of a material to indentation. This is the usual type of hardness test, in which a pointed or rounded indenter is pressed into a surface under a substantially static load.

Induction Hardening

A process of hardening a ferrous alloy by heating it above the transformation range by means of electrical induction, and then cooling as required.

Induction Heating

A process of heating by electrical induction.

Ingot

A casting for subsequent rolling or forging.

Inhibitor

A substance which retards some specific chemical reaction. Pickling inhibitors retard the dissolution of metal without hindering the removal of scale from steel.

Interleaving

The placing of a sheet of paper between two adjacent layers of metal to facilitate handling and shearing of rectangular sheets, or to prevent sticking or scratching.

Intermediate Annealing

An annealing treatment given to wrought metals following cold work hardening for the purpose of softness prior to further cold working. (See Process Annealing)

Interrupted Aging

The aging of an alloy at two or more temperatures by steps, and cooling to room temperatures after each step. Compare with Progressive Aging.

Iron

(Chemical Symbol Fe.) Element No. 26 of the periodic system; Atomic weight 55.85. A magnetic silver-white metal of high tensile strength ductile and malleable. Melting point of pure iron about 2795°F. Chemically iron is chiefly base forming. The principal forms of commercial iron are steel, cast iron and wrought iron.

Ironing

Thinning the walls of deep drawn articles by reducing the clearance between punch and die.

Isothermal Annealing

A process on which a ferrous alloy is heated to produce a structure partly or wholly austenitic, and is then cooled to and held at a temperature that causes transformation of the austenite to a relatively soft ferrite-carbide aggregate.

J

Jig Saw Steel

Hardened, tempered and bright polished with round edges. Carbon content .85%. Range of sizes .039 to .393” in width and .016 to .039” in thickness.

K

Killed Steel

The term “killed” indicates that the steel has been sufficiently deoxidized to quiet the molten metal when poured into the ingot mold. The general practice is to use aluminum ferrosilicon or manganese as deoxidizing agents. A properly killed steel is more uniform as to analysis and is comparatively free from aging. However, for the same carbon and manganese content Killed Steel is harder than Rimmed Steel. In general all steels above 0.25% carbon are killed, also all forging grades, structural steels from 0.15% to 0.25% carbon and some special steels in the low carbon range. Most steels below 0.15% carbon are rimmed steel.

L

Ladle Analysis

A term applied to the chemical analysis representative or in layers, as reported by the producer. Results are determined by analyzing a test ingot sample obtained during the pouring of the steel from a ladle.

Laminations

A defect appearing in sheets or strips as a segregation or in layers. To become divided, caused by gas pockets in the ingot. (See Cold Shut)

Lap

A surface defect appearing as a seam, caused by folding over hot metal, fins or sharp corners and then rolling or forging them into the surface but not welding them.

Lap-Weld

A term applied to a weld formed by lapping two pieces of metal and then pressing or hammering, and applied particularly to the longitudinal joint produced by a welding process for tubes or pipe, in which the edges of the skelp are beveled or scarfed so that when they are overlapped they can be welded together.

Lattice

Space lattice. Lattice lines and lattice planes are lines and planes chosen so as to pass through collinear lattice points, and noncollinear lattice points, respectively.

Lead Annealing

(See Bath Annealing)

Leveling

Flattening rolled metal sheet or strip. (See Roller and Stretcher Leveling)

Light Metals

Metals and alloys that have a low specific gravity, such as beryllium, magnesium and aluminum.

Lithographic Sheet Aluminum

Sheet having a superior surface on one side with respect to freedom from surface imperfections and supplied with a maximum degree of flatness, for use as a plate in offset printing.

Long Terne

A term applying to steel sheets that have been terne coated (Lead and Tin) by immersion in a bath of Terne Metal. (See Terne Plate)

Low Brass – 80% Cu.

A copper–zinc alloy containing 20% zinc. Is a light golden color, very ductile, suitable for cupping, drawing, forming, etc. Because of its good strength and corrosion resistance it is used for flexible metal hoses, metal bellows, etc.

Low Carbon Steels

Contain from 0.10 to 0.30% carbon and less than 0.60% manganese. (The product of Basic Oxygen, Bessemer, Open Hearth or Electric Processes.)

Luders Lines

(Steel) – Characteristic of No. 5 Temper – Not a defect in No. 5 dead soft temper. Long vein-like marks appearing on the surface of certain metals, in the direction of the maximum shear stress, when the metal is subjected to deformation beyond the yield point. Also called stretcher strains, similar occurrence in certain aluminum alloys, etc. (See Stretcher Strains)

Luster Finish

Refer to FINISHES.

M

M B Grade

A term applied to Open-Hearth steel wire in the .45/75 carbon range either hard drawn or oil tempered. Oil tempered wire of M B and W M B types are the most widely used of all spring wire. Oil tempered wire is more suitable to precision forming and casting operations than hard drawn wire because of close control of tensile strength and superior straightness. NOTE – M B, H B and extra H B designate Basic Open Hearth steels, while W M B, W H B and extra W H B designate Acid Open Hearth Steels. The chemical composition and the mechanical properties are the same for both basic and acid steel.

Macroetch Test

Consists of immersing a carefully prepared section of the steel in hot acid and of examining the etching surface to evaluate the soundness and homogeneity of the product being tested.

Macrograph

A photographic reproduction of any object that has not been magnified more than ten times.

Macroscopic

Visible either with the naked eye or under low magnification (as great as about ten diameters).

Macrostructure

The structure of metal as revealed by macroscopic examination.

Magnesium

(Chemical symbol Mg.) – Element No. 12 of the periodic system; atomic weight 24.305. Specific gravity 1.77 with a melting point of approximately 1160°F. A silver-white light malleable, ductile metallic element that occurs abundantly in nature. The metal is used in metallurgical and chemical processes; in photography, in signaling, and in the manufacture of pyrotechnics because of the intense white light it produces on burning. MetalMart is the world’s largest stocking distributor of Magnesium Alloys including; Sheet, Plate, Bar, Castings, Forgings, and Extrusions. Check out our Magnesium page for complete details.

Malleability

The property that determines the ease of deforming a metal when the metal is subjected to rolling or hammering. The more malleable metals can be hammered or rolled into thin sheet more easily than others.

Malleabilizing

A process of annealing white cast iron in such a way that the combined carbon is wholly or partly transformed to graphitic or free carbon or in some instances, part of the carbon is removed completely.

Manganese

(Chemical symbol Mn.) – Element No. 25 of the periodic system; atomic weight 54.93. Lustrous, reddish-white metal of hard brittle and, therefore, non-malleable character. The metal is used in large quantities in the form of Spiegel and Ferromanganese for steel manufacture as well as in manganese and many copper-base alloys. Its principal function is as an alloy in steel making: (1) It is a ferrite-strengthening and carbide forming element. It increases hardenability inexpensively, with a tendency toward embrittlement when too high carbon and too high manganese accompany each other. (2) It counteracts brittleness from sulfur.

Martensite

A distinctive needle like structure existing in steel as a transition stage in the transformation of austenite. It is the hardest constituent of steel of eutectoid composition. It is produced by rapid cooling from quenching temperature and is the chief constituent of hardened carbon tool steels. Martensite is magnetic.

Martensitic Stainless Steel

Has a body centered tetragonal (BCT) structure. These alloys are chromium stainless steels with medium to high carbon levels. They work harden slowly in the annealed (soft) condition but can be heat-treated to very high tensile strengths.

Matrix

The principal phase in which another constituent is embedded.

Matt or Matte Finish

(Steel) – Not as smooth as normal mill finish. Produced by etched or mechanically roughened finishing rolls.

Mechanical Properties

Those properties of a material that reveal the elastic and inelastic reaction when force is applied, or that involve the relationship between stress and strain; for example, the modulus of elasticity, tensile strength and fatigue limit. These properties have often been designated as “physical properties,” but the term “mechanical properties” is much to be preferred. The mechanical properties of steel are dependent on its microstructure. (See Physical Properties)

Mechanical Spring

Any spring produced by cold forming from any material with or without subsequent heat treatment.

Mechanical Working

Plastic deformation or other physical change to which metal is subjected, by rolling, hammering, drawing, etc. to change its shape, properties or structure.

Medium-Carbon Steel

Contains from 0.30% to 0.60% carbon and less than 1.00% manganese. May be made by any of the standard processes.

Melting Range

The range of temperature in which an alloy melts, that is the range between solidus and liquidus temperatures.

Metallography

The science concerning the constituents and structure of metals and alloys as revealed by the microscope.

Metalloid

(a) Element intermediate in luster and conductivity between the true metals and non-metals. Arsenic, antimony, boron, tellurium, and selenium, etc., are generally considered metalloids; frequently one allotropic modification of an element will be non-metallic, another metalloid in character. Obviously, no hard and fast line can be drawn. (b) In steel metallurgy, metalloid in has a specialized, even of erroneous, meaning; it covers elements commonly present in simple steel; carbon, manganese, phosphorus, silicon and sulfur.

Metal Spraying

A process for applying a coating of metal to an object. The metal, usually in the form of wire, is melted by an oxyhydrogen or oxyacetylene blast or by an electric arc and is projected at high speed by gas pressure against the object being coated.

Microstructure

The structure of polished and etched metal and alloy specimens as revealed by the microscope.

Mill Edge

The edge of strip, sheet or plate in the as rolled state. Unsheared.

Mill Finish

A surface finish produced on sheet and plate. Characteristic of the ground finish used on the rolls in fabrication.

Modulus of Elasticity

(Tension) – Force which would be required to stretch a substance to double its normal length, on the assumption that it would remain perfectly elastic, i.e., obey Hooke’s Law throughout the test. The ratio of stress to strain within the perfectly elastic range.

Modulus of Rigidity

Of a material suffering shear, the ratio of the intensity of the shear stress across the section to the shear strain, i.e., to the angle of distortion in radians; expressed in pounds or tons per square inch.

Mold

A form or cavity into which molten metal is poured to produce a desired shape.

Molybdenum

(Chemical Symbol Mo) – Element No. 42 of the periodic system; atomic weight 95.95. Hard, tough metal of grayish-white color, becoming very ductile and malleable when properly treated at high temperatures; melting point 4748°F; boiling point about 6600°F; specific gravity 10.2. Pure molybdenum can best be obtained as a black powder, by reduction of molybdenum trioxide or ammonium molybdate with hydrogen. From this powder, ductile sheet and wire are made by powder metallurgy techniques; these are used on radio and related work. Its principal functions as an alloy in steel making: (1) Raises grain-coarsening temperature of austenite. (2) Deepens hardening. (3) Counteracts tendency toward temper brittleness. (4) Raises hot and creep strength, red hardness. (5) Enhances corrosion resistance in stainless steel. (6) Forms abrasion-resisting particles.

Muntz Metal

(A Refractory Alloy) – Alpha-beta brass, 60% copper and 40% zinc. Stronger than alpha-brass and used for castings and hot-worked (rolled, stamped, or extruded) products. High strength brasses are developed from this by adding other elements.

Music Wire

A polished high tensile strength cold drawn wire with higher tensile strength and higher torsional strength than any other material available. The high toughness characteristic of this material is obtained by the patenting. Such wire is purchased according to tensile strength, not hardness.

N

Natural Aging

Spontaneous aging of a supersaturated solid solution at room temperature.

Needle Cutter Steel

Usually supplied quarter hard rolled, extra precision rolled with sheared edges. Carbon content 1.25% – Chromium .15%. Usually supplied in a 2” width from .002 to .035”. Used for cutting the eye of needle and milling the latch in a latch needle.

Network Structure

A structure in which the crystals of one constituent are surrounded by envelopes of another constituent which gives a network.

Nickel

(Chemical symbol Ni) – Element No. 28 of the periodic system; atomic weight 58.69. Silvery white, slightly magnetic metal, of medium hardness and high degree of ductility and malleability and resistance to chemical and atmospheric corrosion; melting point 2651°F; boiling point about 5250°F; specific gravity 8.90. Used for electroplating. Used as an alloying agent, it is of great importance in iron-base alloys in stainless steels and in copper-base alloys such as Cupro-nickel, as well as in nickel-base alloys such as Monel Metal. Its principal functions as an alloy in steel making: (1) Strengthens unquenched or annealed steels. (2) Toughens pearlitic-ferritic steels (especially at low temperature). (3) Renders high-chromium iron alloys austenitic.

Nickel Silver

Copper base alloys that contain 10-45% Zn. and 5-30% Ni.

Nickel Steel

Steel containing nickel as an alloying element. Varying amounts are added to increase the strength in the normalized condition to enable hardening to be performed in oil or air instead of water.

Nitriding

Process of surface hardening certain types of steel by heating in ammonia gas at about 935-1000°F. The increase in hardness being the result of surface nitride formation. Certain alloying constituents, principal among them being aluminum, greatly facilitate the hardening reaction. In general, the depth of the case is less than with carburizing.

Nitriding Steel

Steel which is particularly suited for the nitriding process, that is, it will form a very hard and adherent surface upon proper nitriding (heating in a partially dissociated atmosphere of ammonia gas). Composition usually .20-.40% carbon, .90-1.50% chromium, .15-1.00% molybdenum, and .85-1.20% aluminum.

Non-Ferrous Metals

Metals or alloys that are free of iron or comparatively so.

Non-Metallic Inclusions

Impurities (commonly oxides), sulphides, silicates or similar substances held in metals mechanically during solidification or formed by reactions in the solid state.

Non-Refractory Alloy

A term opposed to refractory alloy. A non-refractory alloy has malleability, that is, ease of flattening when subjected to rolling or hammering.

Non-Scalloping Quality Strip Steel

Strip steel ordered or sold on the basis of absence of unevenness, or ears, on the edges of the steel, when subjected to deep drawing.

Normalizing

A heat treatment applied to steel. Involves heating above the critical range followed by cooling in still air. Is performed to refine the crystal structure and eliminate internal stress.

Number as Pertaining to Edge

(See Edge)

Number as Pertaining to Hardness

In copper base alloys industry; temper is referred to as so many numbers hard, i.e.; Yellow Brass Half Hard is termed 2 numbers hard. This term is derived from terminology used on the mill floor whereby temper or hardness is imparted by cold working and classified as to hardness by the number of Brown & Sharpe gages away from the soft or as-annealed state.

Number as Pertaining to Temper

(See Temper)

O

Oil Hardening

A process of hardening a ferrous alloy of suitable composition by heating within or above the transformation range and quenching in oil.

Oil-Hardening Steel

Steel adaptable to hardening by heat treatment and quenching in oil.

Oil Stain Aluminum

Stain produced by the incomplete burning of the lubricants on the surface of the sheet. Rolling subsequent to staining will change color from darker browns to lighter browns down to white.

Olsen (Ductility) Test

A method of measuring the ductility and drawing properties of strip or sheet metal which involves determination of the width and depth of impression. The test simulating a deep drawing operation is made by a standard steel ball under pressure, continuing until the cup formed from the metal sample fractures. Readings are in thousandths of an inch. This test is sometimes used to detect stretcher straining and indicates the surface finish after drawing, similar to the Erichsen ductility test.

Open-Hearth Process

Process of making steel by heating the metal in the hearth of a regenerative furnace. In the basic open-hearth steel process, the lining of the hearth is basic, usually magnesite; whereas in the acid open-hearth steel process, an acid material, silica, is used as the furnace lining and pig iron, extremely low in phosphorous (less than 0.04%), is the raw material charged in.

Open Surface

Rough surface on black plate, sheet or strip, resulting from imperfections in the original steel bars from which the plate was rolled.

Orange Peel

(Effect) – A surface roughening (defect) encountered in forming products from metal stock that has a coarse grain size. It is due to uneven flow or to the appearance of the overly large grains usually the result of annealing at too high a temperature. Also referred to as “pebbles” and “alligator skin.”

Ore

A mineral from which metal is (or may be) extracted.

Orientation

(Crystal) – Arrangement of certain crystal axes or crystal planes in a polycrystalline aggregate with respect to a given direction or plane. If there is any tendency for one arrangement to predominate, it is known as the preferred orientation. In the absence of any such preference, random orientation exists.

Oscillated Wound or Scroll Wound

A method of even winding metal strip or wire on to a reel or mandrel wherein the strands are uniformly overlapped. Sometimes termed “stagger wound” or “vibrated wound.” The opposite of ribbon wound.

Overaging

Aging under conditions of time and temperature greater than those required to obtain maximum strength.

Oxidation

The addition of oxygen to a compound. Exposure to atmosphere sometimes results in oxidation of the exposed surface, hence a staining or discoloration. This effect is increased with temperature increase.

Oxide

Compound of oxygen with another element.

Oxygen Lance

A length of pipe used to convey oxygen onto a bath of molten metal.

P

Pack Rolling

Rolling two or more pieces of thin sheet at the same time, a method usually practiced in rolling sheet into thin foil.

Pass

A term indicating the process of passing metal through a rolling mill.

Patenting

Treatment of steel, usually in wire form, in which the metal is gradually heated to about 1830°F, with subsequent cooling, usually in air, in a bath of molten lead, or in a fused salt mixture held between 800°F and 1050°F.

Patent Leveling

(See Stretcher Leveling)

Patterned or Embossed Sheet

A sheet product on which a raised or indented pattern has been impressed on either one or both surfaces by the use of rolls.

Pearlite

Lamellar structure resembling mother of pearl. A compound of iron and carbon occurring in steel as a result of the transformation of austenite into aggregations of ferrite and iron carbide.

Permalloy

Nickel alloys containing about 20 to 60% Fe, used for their high magnetic permeability and electrical resistivity.

Permanent Set

Non-elastic or plastic, deformation of metal under stress, after passing the elastic limit.

Phosphor Bronze

Copper base alloys, with 3.5 to 10% of tin, to which has been added in the molten state phosphorous in varying amounts of less than 1% for deoxidizing and strengthening purposes. Because of excellent toughness, strength, fine grain, resistance to fatigue and wear, and chemical resistance, these alloys find general use as springs and in making fittings. It has corrosion resisting properties comparable to copper.

Phosphor Bronze Strip

A copper-based alloy containing up to 10% tin, which has been deoxidized with phosphorous in varying amounts of less than 1 % (see Phosphor Bronze). Temper is imparted by cold rolling, resulting in greater tensile strength and hardness than in most copper-base alloys or either of its alloying elements copper or tin. The various tempers from “One Number Hard” to “Ten Numbers Hard” are classified in hardness by the number of B & S Gages reduction in dimension from the previous soft or as annealed state (See Brown & Sharpe Gages). Phosphor Bronze is not heat treatable for purposes of hardness development. It does not withstand elevated temperatures very well and should not be used in service above 225°F. even after stress relieving treatment at 325 to 350°F. It has excellent electrical properties, corrosion resistant comparable to copper; great toughness and resistance to fatigue. Rated good for soft soldering, silver alloy brazing, oxyacetylene, carbon arc and resistance welding.

Phosphorus

(Chemical symbol P) – Element No. 15 of the periodic system; atomic weight 30.98. Non-metallic element occurring in at least three allotropic forms; melting point 111°F.; boiling point 536°F.; specific gravity 1.82. In steels it is usually undesirable with limits set in most specifications. However, it is specified as an alloy in steel to prevent the sticking of light-gage sheets; to a degree it strengthens low carbon steel; increases resistance to corrosion, and improves machinability in free-cutting steels. In the manufacture of Phosphor Bronze it is used as a deoxidizing agent.

Photomicrograph

A photographic reproduction of any object magnified more than ten diameters. The term micrograph may be used.

Physical Properties

Those properties familiarly discussed in physics, exclusive of those described under mechanical properties; for example, density, electrical conductivity, co-efficient of thermal expansion. This term often has been used to describe mechanical properties, but this usage is not recommended. (See Mechanical Properties)

Pickling

The process of chemically removing oxides and scale from the surface of a metal by the action of water solutions of inorganic acids.

Pickling Patch

A defect in tin plate, galvanized or terne plated steel due to faulty pickling, leaving areas from which the oxide has not been completely removed.

Pig Iron

Iron produced by reduction of iron ore in a blast furnace. Pig iron contains approximately 92% iron and about 3.5% carbon. The balance is largely silicone and manganese with a small percentage of phosphorus, sulphur, and other impurities.

Pinch Pass Temper

(See Soft Skin Rolled Temper and/or Temper Rolling)

Pinchers

Long fern like creases usually diagonal to the direction of rolling.

Pinhole

Microscopic imperfections of the coatings, that is, microscopic bare spots, also microscopic holes penetrating through a layer or thickness of light gage metal.

Pipe

(Defect) – Contraction cavity, essentially cone-like in shape, which occurs in the approximate center, at the top and reaching down into a casting; caused by the shrinkage of cast metal.

Pit

(Defect) – A sharp depression in the surface of the metal.

Planimetric Method

A method of measuring grain size, in which the grains within a definite area are counted.

Plastic Deformation

Permanent distortion of a material under the action of applied stresses.

Plasticity

The ability of a metal to be deformed extensively without rupture.

Plating

A thin coating of metal laid on another metal. (See Electroplating, Galvanizing, Tinning and Tinplating)

Polished Surface

(Buffed Surface) – The finish obtained by buffing with rouge or similar fine abrasive, resulting in a high gloss or polish.

Polymorphism

The ability of a material to exist in more than one crystallographic structure. Numerous metals change in crystallographic structure at transformation temperatures during heating or cooling. If the change is reversible, it is allotropy. The allotropy of iron, particularly the changes between the alpha body-centered and the gamma face centered form, is of fundamental importance in the hardening of steel.

Pot

A vessel for holding molten metal. Also used to refer to the electrolytic reduction cell employed in winning certain metals, such as aluminum, from a fused electrolyte.

Pot Annealing

Is the same as Box Annealing.

Pouring

The transfer of molten metal from the ladle into ingot molds or other types of molds; for example, in castings.

Powder Metallurgy

The art of producing metal powders and of utilizing metal powders for the production of massive materials and shaped objects.

Precipitation Hardening

A process of hardening an alloy in which a constituent precipitates from a supersaturated solid solution. (See also Age Hardening and Aging)

Precipitation Heat Treatment

Any of the various aging treatments conducted at elevated temperature to improve certain of the mechanical properties through precipitation from solid solution. (See Artificial Aging, Interrupted Aging, and Progressive Aging)

Preheating

(1) A general term used to describe heating applied as a preliminary to some further thermal or mechanical treatment. (2) A term applied specifically to tool steel to describe a process on which the steel is heated slowly and uniformly to a temperature below the hardening temperature and is then transferred to a furnace in which the temperature is substantially above the preheating temperature. (3) Heating a metal to a relatively high temperature for a relatively long time in order to change the structure before working. Ingots are homogenized by preheating.

Primes

Metal products, such as sheet and plate, of the highest quality and free from visible surface defects.

Process Annealing

In the sheet and wire industries, a process by which a ferrous alloy is heated to a temperature close to, but below, the lower limit of the transformation range and is subsequently cooled. This process is applied in order to soften the alloy for further cold working.

Progressive Aging

An aging process in which the temperature of the alloy is continually increased during the aging cycle. The temperature may be increased in steps or by any other progressive method.

Proportional Limit

The greatest stress that the material is capable of sustaining without a deviation from the law of proportionality of stress to strain. (Hooke’s Law)

Punch

The movable part that forces the metal into the die in equipment for sheet drawing, blanking, coining, embossing and the like.

Punching

Shearing holes in sheet metal with punch and die.

Pyrometer

An instrument of various types used for measuring temperatures.

Q

Quarter Hard (No 3 Temper)

(A) In low carbon cold-rolled strip steel, a medium soft temper produced by a limited amount of cold rolling after annealing. (B) In brass mill terminology. Quarter-Hard is one B and S number hard or 10.95% reduction. (C) In stainless steel terminology tempers are based on minimum tensile, or yield strength. For Chromium–Nickel grades Quarter Hard Temper is 125,000 T.S., 75,000 Y.S. min.

Quenching

In the heat treating of metals, the step of cooling metals rapidly in order to obtain desired properties; most commonly accomplished by immersing the metal in oil or water. In the case of most copper base alloys, quenching has no effect other than to hasten cooling.

Quench Hardening

(Steel) – A process of hardening a ferrous alloy of suitable composition by heating within or above the transformation range and cooling at a rate sufficient to increase the hardness substantially. The process usually involves the formation of martensite.

R

Radiant Tube Annealing Box

(See Annealing) – A box which is heated, inside, by means of tubes on which gas is burned; the hot tubes radiate their heat to the covered pile of metal, standing on the base of the box. Usually a protective atmosphere is maintained in the box to protect the metal from oxidation.

Radiography

A nondestructive method of internal examination in which metal objects are exposed to a beam of X-ray or gamma radiation. Differences in thickness, density or absorption, caused by internal defects or inclusions, are apparent in the shadow image either on a fluorescent screen or on photographic film placed behind the object.

Ragged Edges

Edges of sheet or strip which are torn, split, cracked, ragged or burred or otherwise disfigured.

Reciprocal Lattice

(For a crystal) – A group of points arranged about a center in such a way that the line joining each point to the center is perpendicular to a family of planes in the crystal, and the length of this line is inversely proportional to their interplanar distance.

Recovery

The removal of residual stresses by localized plastic flow as the result of low-temperature annealing operations performed on cold worked metals without altering the grain structure or strength properties substantially.

Recrystallization

A process whereby a distorted grain structure of cold worked metals is replaced by a new, stress-free grain structure as a result of annealing above a specific minimum temperature for a specific time.

Red Brass

85% Copper – A copper–zinc alloy containing approximately 15% zinc, used for plumbing pipe, hardware, condenser tubes. Because of its color, is used for vanity cases, coins, plaques, badges, etc. It is somewhat stronger than commercial bronze and is hardened more rapidly by cold working.

Red Shortness

Brittleness in steel when it is red hot.

Reduction of Area

The percent of cross-sectional area the metal will “Neck Down” prior to breaking in tension. % R.A. = (Original area – Area after Fracture) × 100

Refining Temperature

A temperature, usually just higher than the transformation range, employed in the heat treatment of steel to refine the structure – in particular, the grain size.

Reflector Sheet

An alclad product containing on one side a surface layer of high-purity aluminum superimposed on a core or base alloy of commercial-purity aluminum or an aluminum–manganese alloy. The high-purity coating imparts good polishing characteristics and the core gives adequate strength and formability.

Refractory

A heat-resistant material, usually nonmetallic, which is used for furnace linings and such.

Refractory Alloy

A term applied to those alloys which due to hardness or abrasiveness present relative difficulty in maintaining close dimensional tolerances.

Rephosphorizing

(Steel) – A Ladle-chemical treatment consisting of the addition of phosphorus as a work hardening agent when temper rolling black plate or sheet steel resulting in greater hardness and stiffness and with a corresponding loss in ductility. NOTE – Black Plate in tempers T5 and T6 (R/B range 68/84) are temper rolled from Rephosphorized steel.

Residual Stress

Macroscopic stresses that are set up within a metal as the result of non-uniform plastic deformation. This deformation may be caused by cold working or by drastic gradients of temperature from quenching or welding.

Residuals

“Incidental” or “tramp” elements not named in a specification. These inclusions are usually due to contaminated scrap.

Resilience

The tendency of a material to absorb energy when deformed elastically and release it upon unloading.

Resistance Welding

A type of welding process in which the work pieces are heated by the passage of an electric current through the contact. Such processes include spot welding, seam or line welding and percussion welding. Flash and butt welding are sometimes considered as resistance welding processes.

Ribbon Wound

A term applied to a common method of winding strip steel layer upon layer around an arbor or mandrel.

Riffles

Waviness at the edge of sheet or strip.

Rimmed Steel

Low-carbon steel in which incomplete deoxidation permits the metal to remain liquid at the top of the ingot, resulting in the formation of a bottom and side rim of considerable thickness. The rim is of somewhat purer composition than the original metal poured. If the rimming action is stopped shortly after pouring of the ingot is completed, the metal is known as capped steel. Most steels below 0.15% carbon are rimmed steels. For the same carbon and manganese content rimmed steel is softer than killed steel.

Ripple

(Defect) – A slight transverse wave or shadow mark appearing at intervals along the piece.

Rockwell Hardness (Test)

A standard method for measuring the hardness of metals. The hardness is expressed as a number related to the depth of residual penetration of a steel ball or diamond cone (“brale”) after a minor load of 10 kilograms has been applied to hold the penetrator in position. This residual penetration is automatically registered on a dial when the major load is removed from the penetrator. Various dial readings combined with different major loads, give “scales” designated by letters varying from “A” to “H”; the “B” and “C” scales are most commonly in use.

Roentgen Rays

(See X-rays)

Roll Forming

An operation used in forming sheet. Strips of sheet are passed between rolls of definite settings that bend the sheet progressively into structural members of various contours, sometimes called “molded sections.”

Rolled Edges

Finished edges, the final contours of which are produced by side or edging rolls. The edge contours most commonly used are square corners, rounded corners and rounded edge.

Rolled In Scale

A surface defect consisting of scale partially rolled into the surface of the sheet.

Roller Leveling

Passing sheet or strip metal through a series of staggered small rolls so as to flatten the metal. This method is relatively ineffective in removing defects such as buckles, wavy edges, corrugations, twists, etc., or from steel in the higher hardness ranges.

Rolling

A term applied to the operation of shaping and reducing metal in thickness by passing it between rolls which compress, shape and lengthen it following the roll pattern.

Rolling Direction

(In rolled metal) – The direction, in the plane of the sheet, perpendicular to the axes of the rolls during rolling.

Rolling Mills

Equipment used for rolling down metal to a smaller size or to a given shape employing sets of rolls tie contours of which determine or fashion the product into numerous intermediate and final shapes, e.g., blooms, slabs, rails, bars, rods, sections, plates, sheets and strip.

Rotary Shear

(Slitting Machine) – A cutting machine with sharpened circular blades or disc-like cutters used for trimming edges and slitting sheet and foil. NOTE: Cutter discs are also employed in producing circles from flat sheets but with differently designed machines.

Rule Die Steel

A hardened and tempered medium high carbon spring steel strip sufficiently low hardness to take moderately sharp bends without fracture, intended for manufacture into rule dies for the purpose of cutting or stamping fabrics, paper, cardboard, plastics, and metal foil into desired shape.

S

SAE

Abbreviation for Society of Automotive Engineers. This organization has specified common and alloy steels and copper base alloys in accordance with a numerical index system allowing approximation of the composition of the metal. The last two digits indicate the carbon content, usually within 0.05%.

Salt Spray Test

An accelerated corrosion test in which the metal specimens are exposed to a fine mist of salt water solution either continuously or intermittently.

Satin Finish

(See Scratch Brushed Finish)

Scab

(Scabby) – A blemish caused on a casting by eruption of gas from the mold face or by uneven mold surface or occurring where the skin from a blowhole has partly burned away and is not welded.

Scale

(See Scaling)

Scaleless Blue

(See Black Oil Tempered Spring Steel)

Scaling

(1) Oxidation of metal due to heat resulting in relatively heavy surface layers of oxide. (2) Removal of scale from metal.

Scallop

(See Ear)

Scalping

Machining the surface layers from ingots, billets and slabs before fabrications.

Scarfing

Cutting surface areas of metal objects, ordinarily by using a gas torch. The operation permits surface defects to be cut from ingots, billets, or the edges of plate that are to be beveled for butt welding. (See Chipping)

Scleroscope Hardness (Test)

A method for measuring the hardness of metal; a diamond-pointed hammer drops from a fixed distance through a tube onto the smoothed metal surface and the rebound distance, with a specified high-carbon steel as 100.

Scrap

Material unsuitable for direct use but usable for reprocessing by remelting.

Scratch Brushed Finish

Finish obtained by mechanically brushing the surface with wire bristle brushes, by buffing with greaseless compound or by cold rolling with wire bristled rolls of scratch etched finish.

Seam

(A defect.) – On the surface of metal a crack that has been closed but not welded; usually produced by some defect either in casting or in working, such as blowholes that have become oxidized or folds and laps that have been formed during working. Similar to cold shut and laminations.

Seam Welding

An electric-resistance type of welding process, in which the lapped sheet is passed between electrodes of the roller type while a series of overlapping spot welds is made by the intermittent application of electric current.

Seconds

The designation given to sheet or strip that has imperfections in moderate degree or extent, which may be classified in two general groups imperfections in the base material, or other manufacturing defects. This term is not used in connection with non-ferrous alloys.

Segment Steel

Used for laminated piston rings. Carbon content about .70%. Hardened and blue tempered with round edges. Hardness usually Rockwell’s 30 N 68 to 71, width sizes vary from .058 to .163” and thickness’ are .020, .024 and .030”.

Segregation

In an alloy, concentration of carbon or alloying elements at specific regions, usually as a result of the primary crystallization of one phase with the subsequent concentration of other elements in the remaining liquid.

Self-Hardening Steel

A steel containing sufficient carbon or alloying element, or both, to form martensite either through air hardening or, as in welding and induction hardening, through rapid removal of heat from a locally heated portion by conduction into the surrounding cold metal. (See Air-Hardening Steel)

Semifinished Steel

Steel in the form of billets, blooms, etc., requiring further working before completion into finished steel ready for marking.

Semikilled Steel

Steel incompletely deoxidized, to permit evolution of sufficient carbon monoxide to offset solidification shrinkage.

Semi-Steel

Cast iron (not steel) of high quality, obtained by using a large percentage of steel scrap with the pig iron.

Shear

A type of cutting operation in which the metal object is cut by means of a moving blade and fixed edge or by a pair of moving blades that may be either flat or curved.

Shear Crack

A diagonal, transgranular track caused by shear stresses.

Shim

A thin flat hard metal strip produced to close tolerances; used primarily for tool, die and machine alignment purposes. In steel there are four general types: (1) Low Carbon Rockwell B 80/100; (2) Hard Rolled High Carbon Rockwell C 28/33; (3) Hardened and Tempered Spring Steel Rockwell C 44/51; (4)Austinitic Stainless Steel Rockwell C 35/45. Brass shim of commercial quality is also used and most generally specified as 2 Nos. Hard but may be 4 Nos. Hard.

Shore Hardness Test

(See Scleroscope Hardness)

Short

(See Brittleness)

Short Terne

A term applying to terne coated (Lead and Tin) sheets with reference to Base Box sizes (14” x 20”). (See Terne Plate)

Shot Blasting

Cleaning surface of metal by air blast, using metal shot as an abrasive.

Shrinkage Cavity

A void left in cast metals as a result of solidification shrinkage and the progressive freezing of metal towards the center.

Silicon

(Chemical Symbol Si) – Element No. 14 of the periodic system; atomic weight 28.06. Extremely common element, the major component of all rocks and sands; its chemical reactions, however, are those of a metalloid. Used in metallurgy as a deoxidizing scavenger. Silicon is present, to some extent, in all steels, and is deliberately added to the extent of approximately 4% for electric sheets, extensively used in alternating current magnetic circuits. Silicon cannot be electrodeposited.

Silicon Steel

Steel usually made in the basic open-hearth or electric furnace, with about 0.50-5.% silicon, other elements are usually kept as low as possible. Because of high electrical resistance and low hysteresis loss, silicon sheet and strip are standard in electric magnet manufacture.

Silky Fracture

A steel fracture that has a very smooth fine train or silky appearance.

Silver Solders

Alloys of silver, copper, zinc and other metals, melting between 650 and 875°C. used for making strong yet moderately ductile joints that resist corrosion.

Single-Action Press

A forming press that operates with a single function, such as moving a punch into a die with no simultaneous action for holding down the clank or ejecting the formed work.

Sinker Steel

Used for making sinkers in hosiery making machinery. Supplied both hardened and tempered and cold rolled and annealed. Usually extra precision rolled and extra flat. Carbon content about 1.25%.

Sinkhead or Hot Top

A reservoir insulated to retain heat and to hold excess molten metal on top of an ingot mold in order to feed the shrinkage of the ingot. Also called “shrink head” or “feeder head.”

Sintered Carbide

Composite, containing carbides of extremely refractory metals, such as tungsten, tantalum, titanium, etc., cemented together by a relatively low-melting metal, such as cobalt acting as a matrix.

Sintering

Converting powder into a continuous mass by heating to a temperature considerably below fusion, usually after preliminary compacting by pressure.

Skelp

A plate of steel or wrought iron from which pipe or tubing is made by rolling the skelp into shape longitudinally and welding or riveting the edges together.

Skin

A thin surface layer that is different from the main mass of a metal object, in composition structure or other characteristics.

Slab

(See Bloom)

Slag

A product resulting from the action of a flux on the nonmetallic constituents of a processed ore, or on the oxidized metallic constituents that are undesirable. Usually slags consist of combinations of acid oxides with basic oxides, and neutral oxides are added to aid fusibility.

Slit Edges

The edges of sheet or strip metal resulting from cutting to width by rotary slitters.

Slitting

Cutting sheet or strip metal to width by rotary slitters.

Sliver

(Defect) – Loose metal piece rolled down onto the surface of the metal during the rolling operations.

Soaking

Prolonged heating of a metal at selected temperature.

Soft Skin Rolled Temper

(No.4 Temper) – In low carbon-rolled strip steel, soft and ductile. Produced by subjecting annealed strip to a pinch pass or skin rolling (a very light rolling).

Solder Embrittlement

Reduction in ductility of a metal or alloy, associated with local penetration by molten solder along grain boundaries.

Soldering

Joining metals by fusion of alloys that have relatively low melting points most commonly, lead-base or tin-base alloys, which are the soft solders. Hard solders are alloys that have silver, copper, or nickel bases and use of these alloys with melting points higher than 800°F. is generally termed brazing.

Solution Heat Treatment

A process in which an alloy is heated to a suitable temperature, is held at this temperature long enough to allow a certain constituent to enter into solid solution and is then cooled rapidly to hold the constituent in solution. The metal is left in a supersaturated, unstable state and may subsequently exhibit age hardening.

Sorbite

Structure of steel, resulting from the tempering of martensite. In a truly sorbitic structure, the cementite is completely dispersed in the matrix. The trend is to call this structure tempered martensite.

Sorbitic Pearlite

Structure of steel resulting, on cooling under the proper conditions from the decomposition of austenite; has a fine, Lamellar appearance.

Space-Centered

(Concerning space lattices) – Body-centered.

Space Lattice

(Crystal) – A system of equivalent points formed by the intersections of three sets of planes parallel to pairs of principal axes; the space lattice may be thought of as formed by the corners of the unit cells.

Specific Gravity

A numerical value representing the weight of a given substance as compared with the weight of an equal volume of water, for which the specific gravity is taken as 1.0000.

Spectrograph

(X-rays) – An instrument using an extended surface – a photographic plate or film, or a fluorescent screen – for receiving the X-ray diffraction pattern.

Spelter

(Prime Western Specter). A low-grade of Virgin Zinc containing approximately 98% Zinc used in Galvanizing processes.

Spheroidizing

Any process of prolonged heating and slow cooling of steel which will convert the carbide content into rounded or spheroid form.

Spiegel

High-manganese pig iron, containing 15-30% manganese, approximately 5% carbon, and less than 1% silicon, used in the manufacture of steel by the Bessemer, or basic open-hearth process.

Spinning

The procedure of making sheet metal discs into hollow shapes by pressing the metal against a rotating form (spinning chuck) by a tool.

Spot Welding

An electric-resistance welding process in which the fusion is limited to a small area. The pieces being welded are pressed together between a pair of water-cooled electrodes through which an electrical current is passed during a very short interval so that fusion occurs over a small area at the interface between the pieces.

Spring-Back

An indicator of elastic stresses, frequently measured as the increase in diameter of a curved strip after removing it from the mandrel about which it was held. The measurement is employed as an indicator of the extent of recovery or relief of residual stresses that has been achieved by the transformation of elastic strain to plastic strain during heating or stress relieving.

Spring Steel

Steel, normally of the high-carbon or alloy type, used in the manufacture of springs, lending itself to appropriate heat treatment; usually made is the open hearth or electric furnace.

Spring Steel Strip

Any of a number of strip steels produced for use in the manufacture of steel springs or where high tensile properties are requires marketed in the annealed state, hard rolled or as hardened and tempered strip.

Spring Temper

In brass mill terminology, Spring Temper is eight numbers hard or 60.50% reduction.

Stabilizing Anneal

A treatment applied to austentic stainless steels that contain titanium or columbium. This treatment consists of heating to a temperature below that of a full anneal in order to precipitate the maximum amount of carbon at titanium carbide or columbium carbide. This eliminates precipitation at lower temperatures, which might reduce the resistance of the steel to corrosion.

Stabilizing Treatment

A thermal treatment designed to precipitate material from solid solution, in order to improve the workability, to decrease the tendency of certain alloys to age harden at room temperature, or to obtain dimensional stability under service at slightly elevated temperatures.

Stainless Steel

Corrosion resistant steel of a wide variety, but always containing a high percentage of chromium. These are highly resistant to corrosion attack by organic acids, weak mineral acids, atmospheric oxidation, etc.

Stamping

A term used to refer to various press forming operations in coining, embossing, blanking, and pressing.

Steam Blued

(See Bluing)

Steel

Iron, malleable in at least one range of temperature below its melting point without special heat treatment substantially free from slag, and containing carbon more than about 0.05% and less than about 2.00%. Other alloying elements may be present in significant quantities, but all steels contain at least small amounts of manganese and silicon, and usually as undesirable constituents, also sulfur and phosphorus.

Sticker

Steel sheets or strip adhering. Usually by fusion spots caused by overheating during box annealing.

Straight-Chrome

An iron alloy. A term indicating a group of stainless steels the principal alloying element of which is chromium in varying amounts from 4.00 to 27.00%.

Strain

Deformation produced on a body by an outside force. (See also Stress and Hooke’s Law.)

Strain Aging

Aging induced by cold working. (See Aging)

Strain Hardening

An increase in hardness and strength caused by plastic deformation at temperatures lower than the recrystallization range.

Stress

Deforming force to which a body is subjected or the resistance which the body offers to deformation by the force. (See also Strain and Hooke’s Law)

Stress Relief

Low temperature annealing for removing internal stresses, such as those resulting in a metal from work hardening or quenching.

Stress Relieving

Reducing residual stresses by heating.

Stretch Forming

A process of forming panels and cowls of large curvature by stretching sheet over a form of the desired shape. This method is more rapid than hammering and beating.

Stretcher Leveling

(Also termed “patent leveling.”) A method of making metal sheet or strip dead flat by stretching.

Stretcher Strains

Long vein-like marks appearing on the surface of certain metals, in the direction of the maximum shear stress, when the metal is subjected to deformation beyond the yield point. Also termed Luders Lines. (Not a defect in No. 5 dead soft temper.)

Strip Steel

(Cold Rolled) – A flat cold rolled steel product (Other than Flat Wire) 23 15/16” and narrower; under .250’ in thickness, which has been cold reduced to desired decimal thickness and temper on single stand, single stand reversing, or tandem cold mills in coil form from coiled hot rolled pickled strip steel.

Structure

The arrangement of parts; in crystals, especially the shape and dimension of the unit cell, and the number, kinds and positions of the atoms within it.

Sulfur

(Chemical Symbol S.) – Element No. 16 of the periodic system; atomic weight 32.06. Non-metal occurring in a number of allotropic modifications, the most common being a pale-yellow brittle solid. In steel most commonly encountered as an undesired contaminant. However, it is frequently deliberately added to cutting stock to increase machinability.

T

Tandem Mill

Arrangement of rolling mills, in direct line, allowing the metal to pass from one set of rolls into the next.

Tapping

Transferring molten metal from melting furnace to ladle.

Tarnish

Surface discoloration on a metal, usually from a thin film of oxide or sulfide.

Teeming

Pouring metal into ingot molds.

Telescoping

Transverse slipping of successive layers of a coil so that the edge of the coil is conical rather than flat.

Temper

The state of or condition of a metal as to its hardness or toughness produced by either thermal treatment or heat treatment and quench or cold working or a combination of same in order to bring the metal to its specified consistency. Each branch of the metal producing industry has developed its own system of temper designations. (Full table of Aluminum Sheet, Copper Base Alloys, Sheet Steel, Stainless Strip Steel, and Tin Mill Products classifications would follow here, preserving your formatting.)

Tempered and Polished Spring Steel Strip

90/1.03% carbon range (Also known as clock spring steel.) This product, while similar to general description under heading of Tempered Spring Steel Strip, is manufactured and processed with extreme care in each production step. Manufactured from carbon range of .90/1.03% with Rockwell range C 48/51. Supplied dark blue, used for mechanical springs, timing devices, electrical springs, steel tapes, rules, etc.

Tempered Spring Steel Strip

Any medium or high carbon (excluding clock spring) strip steel of spring quality which has been hardened and tempered to meet specifications. Where blue or straw color is specified, color is developed by heating to appropriate temperature (blue ≈ 600°F).

Tempering

(Also termed “drawing.”) A process of reheating quench-hardened or normalized steel below the transformation range and cooling at any rate desired. Used to reduce brittleness of martensite and impart toughness.

Temper Rolling

Subjecting sheet or strip to slight cold rolling (½ to 1½%) following annealing to prevent stretcher strains. Also called “Pinch Pass” or “Skin Rolled.”

Tensile Strength

(Also called ultimate strength) – The maximum stress a material withstands before breaking under tensile load, measured on a standard specimen in a tensile testing machine.

Tensile Test

(See Tensile Strength)

Ternary Alloy

An alloy containing three principal elements.

Terne Plate

Sheet steel coated with a lead-tin alloy, usually ≈15% tin to allow proper alloying with steel surface for adhesion.

Thermocouple

A temperature-measuring device using two dissimilar metals joined at a junction, which generates a measurable voltage with temperature change.

Thickness Gage or Feeler Stock

Hardened, tempered, ground, and polished high-carbon strip steel, usually ½” wide, thickness .001″–.050″, used for measuring gaps, available in holders or coils.

Three-Quarter Hard Temper

(A) Stainless steel strip: minimum 175,000 psi tensile, 135,000 psi yield. (B) Brass mill terminology: three B&S numbers hard (≈29.4% reduction).

Tin

(Chemical Symbol Sn) – Soft silvery-white metal, atomic weight 118.70, melting point 449°F, used chiefly for coating steel (tin plate) and alloying.

Tinning

Coating with tin by immersion, electroplating, or spraying.

Tin Plate Base Box

Unit of measurement for tin plate: 112 sheets (14″×20″), total area 31,360 sq in. Weight ranges 55–275 lb/base box.

Tin Plating

Electroplating metal objects with tin, making the workpiece the cathode in a tin-salt electrolyte bath.

Titanium

(Chemical Symbol Ti) – Strong, corrosion-resistant white metal, melting point ≈3270°F, used in steels to fix carbon, prevent chromium depletion in stainless steels, and for high strength/corrosion-resistant applications.

Tolerance Limit

Permissible deviation from a specified value.

Tool Steel

High carbon or alloy steel capable of being suitably hardened and tempered for making tools.

Toughness

Ability of a metal to absorb energy and resist fracture, usually measured by impact tests.

Trace

Extremely small quantity of an element, usually below quantitative determination limits.

Transformation

A constitutional change in solid metal (e.g., gamma → alpha iron, pearlite formation from austenite).

Transformation Range

Temperature range during which a phase transformation occurs.

Transformation Temperature

Temperature at which a transformation occurs; may also refer to range limits.

Troosite

Tempered martensite that etches rapidly, appears dark, unresolved microscopically.

Trowel Steel

Hardened and tempered spring steel (.90–1.05% C), rolled extra flat, Rockwell C ≈50. Used for plastering trowels.

Truss Spring Steel

Cold-rolled, bright annealed, ≈.70% carbon steel, very ductile, must be decarb-free for severe forming.

Tukon Hardness Test

Micro-hardness test using Knoop diamond or Vickers pyramid indenter.

Tumbling

Cleaning process where parts are rotated in a barrel with abrasive media.

Tungsten

(Chemical Symbol W) – High-tensile gray metal, immune to atmosphere and acids (except strong alkali). Used in lamp filaments, radio tubes, and alloying tool steels.

Tungsten Carbide

Hard compound of tungsten and carbon (WC/W2C), used for cutting tools when sintered in cobalt matrix.

Twist

Winding departure from flatness in strip or sheet.

U

Ultimate Strength

(See Tensile Strength)

Utility Sheet Aluminum

Mill finish coiled or flat sheet of unspecified composition and properties produced in specific standard sizes and suitable for general building trade usage.

Upsetting

(1) A metal working operation similar to forging. (2) The process of axial flow under axial compression of metal, as in forming heads on rivets by flattening the end of wire.

V

Vacuum Degassing

(See Degassing Process)

Vanadium

(Chemical Symbol V) – Element No. 23 of the periodic system; atomic weight 50.95. Gray-white, hard metal, unaffected by atmospheric influences or alkalies but soluble in most strong acids; melting point 31190°F.; boiling point about 61500°F.; specific gravity 5.87. It cannot be electrodeposited. Its principal functions as an alloy in the making of tool steels. (1) Elevates coarsening temperature of austenite (promotes fine grain). (2) Increases hardenability (when dissolved). (3) Resists tempering and causes marked secondary hardening.

Vibrated Wound

(See Oscillated Wound Coils)

Vibrator Reed Steel

Hardened, temper and white polished extra precision rolled. Carbon content about 1.00%. Steel must withstand great fatigue stresses.

Vickers Hardness (Test)

Standard method for measuring the hardness of metals, particularly those with extremely hard surfaces: the surface is subjected to a standard pressure for a standard length of time by means of a pyramid-shaped diamond. The diagonal of the resulting indention is measured under a microscope and the Vickers Hardness value read from a conversion table.

Virgin Metal

Metal obtained directly from ore and not used before.

W

WMB, WHB and EXTRA WHB Grades

Spring steel wires produced from acid open-hearth steels (see notes at M B GRADE).

Wasters

Sheets that have prohibited defects, for example seams and buckled plates. Generally fit for re-melting purposes only.

Watch Main Spring Steel

Usually supplied cold rolled and annealed in large widths and cut and hardened by the spring manufacturers. Carbon content about 1.15% and Tungsten .17%, extra precision rolled.

Water Hardening

Process of hardening high carbon steels by quenching in water or brine after heating.

Wavy

Not flat. A slight wave following the direction of rolling and beyond the standard limitation for flatness.

Wedge

A hardwood stick used as a forming tool in spinning.

Welding

A process used to join metals by the application of heat. Fusion welding, which includes gas, arc, and resistance welding, requires that the parent metals be melted. This distinguishes fusion welding from brazing. In pressure welding joining is accomplished by the use of heat and pressure without melting. The parts that are being welded are pressed together and heated simultaneously, so that recrystalization occurs across the interface.

Work Hardening

Increase in resistant to deformation (i.e. in hardness) produced by cold working.

Workability

The characteristic or group of characteristic that determines the ease of forming a metal into desired shapes.

Worms

(See Stretcher Strains)

Wrought Iron

Iron containing only a very small amount of other elements, but containing 1-3% by weight of slag in the form of particles elongated in one direction, giving the iron a characteristic grain. Is more rust-resistant than steel and welds more easily.

X

X-Rays

Light rays, excited usually by the impact of cathode rays on matter, which have wave lengths between about 10-6 cm, and 10-9 cm; also written X-rays, same as Roentgen rays.

Y

Yield Point

The load per unit of original cross section at which, in soft steel, a marked increase in deformation occurs without increase in load.

Yield Strength (YS)

The stress (load/area) at which the metal changes from elastic to plastic in behavior, i.e., takes a permanent set.

Young’s Modulus

The coefficient of elasticity of stretching. For a stretched wire, Young’s Modulus is the ratio of stretching force per unit cross-sectional area to the elongation per unit length. The values of Young’s Modulus for metals are of the order 10 12 dynes per square cm. (See Modulus of Elasticity)

Z

Zinc

(Chemical Symbol Zn) – Element No. 30 of the periodic system. Atomic weight 65.38. Blue-white metal; when pure, malleable and ductile even at ordinary temperatures; melting point 7870°F., boiling point 16650°F., specific gravity 7.14. It can be electrodeposited and is used extensively as a coating for steel (See Galvanizing) and sheet. Zinc finds many outlets, such as dry batteries, etc. Zinc-base alloys are of great importance in die casting. Its most important alloy is brass.

Zirconium

(Chemical Symbol Zr.) – Element No. 40 of the periodic system. Atomic weight 91.22. Specific gravity 6.5 and melting point at about 3200° +/- 1300°F. Because of its great affinity for oxygen and combines readily with nitrogen and sulfur, it is used as a deoxidizer and scavenger in steel making. It is used as an alloy with nickel for cutting tools and is used in copper alloys.