Hardness Conversions

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Approximate Hardness Conversion No.s for Cartridge Brass (70&perc Cu 30% Zn Alloy)

Vicker’s Hardness Number (HV)	Rockwell Hardness Number B Scale, 100 Kgf (HRB)	Rockwell Hardness Number F Scale, 600 Kgf (HRF)	Rockwell Superficial Hardness No. 15T Scale, 15 Kgf (15T)	Rockwell Superficial Hardness No. 30T Scale, 30 Kgf (30T)	Rockwell Superficial Hardness No. 45T Scale, 45 Kgf (45T)	Brinell Hardness No. 10mm Standard Ball, 500 Kgf (HBS)
196	93.5	110	90	77.5	66	169
194	…	109.5	…	…	65.5	167
192	93	…	…	777	65	166
190	92.5	109	…	76.5	64.5	164
188	92	…	89.5	…	64	162
186	91.5	108.5	…	76	63.5	161
184	91	…	…	75.5	63	159
182	90.5	108	89	…	62.5	157
180	90	107.5	…	75	62	156
178	89	…	…	74.5	61.5	154
176	88.5	107	…	…	61	152
174	88	…	88.5	74	60.5	150
172	87.5	106.5	…	73.5	60	149
170	87	…	…	…	59.5	147
168	86	106	88	73	59	146
166	85.5	…	…	72.5	58.5	144
164	85	105.5	…	72	58	142
162	84	105	87.5	…	57.5	141
160	83.5	…	…	71.5	56.5	139
158	83	104.5	…	71	56	138
156	82	104	87	70.5	55.5	136
154	81.5	103.5	…	70	54.5	135
152	80.5	103	…	…	54	133
150	80	…	86.5	69.5	53.5	131
148	79	102.5	…	69	53	129
146	78	102	…	68.5	52.5	128
144	77.5	101.5	86	68	51.5	126
142	77	101	…	67.5	51	124
140	76	100.5	85.5	67	50	122
138	75	100	…	66.5	49	121
136	74.5	99.5	85	66	48	120
134	73.5	99	…	65.5	47.5	118
132	73	98.5	84.5	65	46.5	116
130	72	98	84	64.5	45.5	114
128	71	97.5	…	63.5	45	113
126	70	97	83.5	63	44	112
124	69	96.5	…	62.5	43	110
122	68	96	83	62	42	108
120	67	95.5	…	61	41	106
118	66	95	82.5	60.5	40	105

Approximate Hardness Conversion Numbers for Nickel & High-Nickel Alloys

Vicker’s Hardness Number (HV)	Brinell Hardness No. 10mm Standard Ball, 3000 Kgf (HBS)	Rockwell Hardness Number A Scale, 60 Kgf (HRA)	Rockwell Hardness Number B Scale, 100 Kgf (HRB)	Rockwell Hardness Number C Scale, 150 Kgf (HRC)	Rockwell Hardness Number D Scale, 100 Kgf (HRD)	Rockwell Hardness Number E Scale, 100 Kgf (HRE)
513	…	75.5	…	50	63	…
481	450	74.5	…	48	61.5	…
452	425	73.5	…	46	60	…
427	403	72.5	…	44	58.5	…
404	382	71.5	…	42	57	…
382	363	70.5	…	40	55.5	…
362	346	69.5	…	38	54	…
344	329	68.5	…	36	52.5	…
326	313	67.5	…	34	50.5	…
309	298	66.5	…	32	49.5	…
285	275	64.5	…	28.5	46.5	…
266	258	63	…	25.5	44.5	…
248	241	61.5	100	22.5	42	…
234	228	60.5	98	20	40	…
220	215	59	96	…	38	…
209	204	57.5	94	…	36	…
198	194	56.5	92	…	34	…
188	184	55	90	…	32	…
179	176	53.5	88	…	30	…
171	168	52.5	86	…	28	…
164	161	51.5	84	…	26.5	…
157	155	50	82	…	24.5	…
151	149	49	80	…	22.5	…
145	144	47.5	78	…	21	…
140	139	46.5	76	…	-19	99.5

Rockwell Hardness Number F Scale, 600 Kgf (HRF)	Rockwell Superficial Hardness No. 15N Scale, 15 Kgf (15N)	Rockwell Superficial Hardness No. 30N Scale, 30 Kgf (30N)	Rockwell Superficial Hardness No. 45N Scale, 45 Kgf (45N)	Rockwell Superficial Hardness No. 15T Scale, 15 Kgf (15T)	Rockwell Superficial Hardness No. 30T Scale, 30 Kgf (30T)	Rockwell Superficial Hardness No. 45T Scale, 45 Kgf (45T)
…	85.5	68	54.5	…	…	…
…	84.5	66.5	52.5	…	…	…
…	83.5	64.5	50	…	…	…
…	82.5	63	47.5	…	…	…
…	81.5	61	45.5	…	…	…
…	80.5	59.5	43	…	…	…
…	79.5	58	41	…	…	…
…	78.5	56	38.5	…	…	…
…	77.5	54.5	36	…	…	…
…	76.5	52.5	34	94.5	85.5	77
…	75	49.5	30	94	84.5	75
…	73.5	47	26.5	93	83	73
…	72	44.5	23	92.5	81.5	71
…	70.5	42	20	92	80.5	69
…	69	39.5	17	91	79	67
…	68	37.5	14	90.5	77.5	65
…	66.5	35.5	11	89.5	76	63
…	65	32.5	7.5	89	75	61
…	64	30.5	5	88	73.5	59.5
…	62.5	28.5	2	87.5	72	57.5
…	61.5	26.5	…	87	70.5	55.5
…	…	…	…	86	69.5	53.5
…	…	…	…	85.5	68	51.5
…	…	…	…	84.5	66.5	49.5
99.5	…	…	…	84	65.5	47.5

Approximate Hardness Conversion No.’s for Austenitic Stainless Steel Sheet

Rockwell Hardness Number B Scale, 100 Kgf (HRB)	Rockwell Hardness Number A Scale, 60 Kgf (HRA)	Rockwell Superficial Hardness No. 15T Scale, 15 Kgf (15T)	Rockwell Superficial Hardness No. 30T Scale, 30 Kgf (30T)	Rockwell Superficial Hardness No. 45T Scale, 45 Kgf (45T)
100	61.5	91.5	80.4	70.2
99	60.9	91.2	79.7	69.2
98	60.3	90.8	79	68.2
97	59.7	90.4	78.3	67.2
96	59.1	90.1	77.7	66.1
95	58.5	89.7	77	65.1
94	58	89.3	76.3	64.1
93	57.4	88.9	75.6	63.1
92	56.8	88.6	74.9	62.1
91	56.2	88.2	74.2	61.1
90	55.6	87.8	73.5	60.1
89	55	87.5	72.8	59
88	54.5	87.1	72.1	58
87	53.9	86.7	71.4	57
86	53.3	86.4	70.7	56
85	52.7	86	70	55
84	52.1	85.6	69.3	54
83	51.5	85.2	68.6	52.9
82	50.9	84.9	67.9	51.9
81	50.4	84.5	67.2	50.9
80	49.8	84.1	66.5	49.9

Approximate Hardness Conversion No.’s for Austenitic Stainless Steel Sheet

Rockwell Hardness Number C Scale, 150 Kgf (HRC)	Rockwell Hardness Number A Scale, 60 Kgf (HRA)	Rockwell Superficial Hardness No. 15N Scale, 15 Kgf (15N)	Rockwell Superficial Hardness No. 30N Scale, 30 Kgf (30N)	Rockwell Superficial Hardness No.45N Scale, 40 Kgf (45N)
48	74.4	84.1	66.2	52.1
47	73.9	73.6	65.3	50.9
46	73.4	83.1	64.5	49.8
45	72.9	82.6	63.6	48.7
44	72.4	82.1	62.7	47.5
43	71.9	81.6	61.8	46.4
42	71.4	81	61	45.2
41	70.9	80.5	61.1	44.1
40	70.4	80	59.2	43
39	69.9	79.5	58.4	41.8
38	69.3	79	57.5	40.7
37	68.8	78.5	56.6	39.6
36	68.3	78	55.7	38.4
35	67.8	77.5	54.9	37.3
34	67.3	77	54	36.1
33	66.8	76.5	53.1	35
32	66.3	75.9	52.3	33.9
31	65.8	75.4	51.4	32.7
30	65.3	74.9	50.5	31.6
29	64.8	74.4	49.6	30.4
28	64.3	73.9	48.8	29.3
27	63.8	73.4	47.9	28.2
26	63.3	72.9	47	27
25	62.8	72.4	46.2	25.9
24	62.3	71.9	45.3	24.8
23	61.8	71.3	44.4	23.6
22	61.3	70.8	43.5	22.5
21	60.8	70.3	42.7	21.3
20	60.3	69.8	41.8	20.2

Approximate Hardness Conversion Numbers for Non-Austenitic Steels

Rockwell B Hardness No. 100 Kgf (HRB)	Vicker’s Hardness Number (HV)	Brinell Hardness No. 10mm Standard Ball, 3000 Kgf (HBS)	Knoop Hardness Number 500 gf & Over (HK)
100	240	240	251
99	234	234	246
98	228	228	241
97	222	222	236
96	216	216	231
95	210	210	226
94	205	205	221
93	200	200	216
92	195	195	211
91	190	190	206
90	185	185	201
89	180	180	196
88	176	176	192
87	172	172	188
86	169	169	184
85	165	165	180
84	162	162	176
83	159	159	173
82	156	156	170
81	153	153	167
80	150	150	164
79	147	147	161
78	144	144	158
77	141	141	155
76	139	139	152
75	137	137	150
74	135	135	147
73	132	132	145
72	130	130	143
71	127	127	141
70	125	125	139
69	123	123	137
68	121	121	135
67	119	119	133
66	117	117	131
65	116	116	129
64	114	114	127
63	112	112	125
62	110	110	124
61	108	108	122
60	107	107	120

Rockwell Hardness Number A Scale, 60 Kgf (HRA)	Rockwell Hardness Number F Scale, 60 Kgf (HRF)	Rockwell Superficial Hardness No. 15T Scale, 15 Kgf (15T)	Rockwell Superficial Hardness No. 30T Scale, 30 Kgf (30T)	Rockwell Superficial Hardness No. 45T Scale, 45 Kgf (45T)
61.5	…	93.1	83.1	72.9
60.9	…	92.8	82.5	71.9
60.2	…	92.5	81.8	70.9
59.5	…	92.1	81.1	69.9
58.9	…	91.8	80.4	68.9
58.3	…	91.5	79.8	67.9
57.6	…	91.2	79.1	66.9
57	…	90.8	78.4	65.9
56.4	…	90.5	77.8	64.8
55.8	…	90.2	77.1	63.8
55.2	…	89.9	76.4	62.8
54.6	…	89.5	75.8	61.8
54	…	89.2	75.1	60.8
53.4	…	88.9	74.4	59.8
52.8	…	88.6	73.8	58.8
52.3	…	88.2	73.1	57.8
51.7	…	87.9	72.4	56.8
51.1	…	87.6	71.8	55.8
50.6	…	87.3	71.1	54.8
50	…	86.9	70.4	53.8
49.5	…	86.6	69.7	52.8
48.9	…	86.3	69.1	51.8
48.4	…	86	68.4	50.8
47.9	…	85.6	67.7	49.8
47.3	…	85.3	67.1	48.8
46.8	99.6	85	66.4	47.8
46.3	99.1	84.7	65.7	46.8
45.8	98.5	84.3	65.1	45.8
45.3	98	84	64.4	44.8
44.8	97.4	83.7	63.7	43.8
44.3	96.8	83.4	63.1	42.8
43.8	96.2	83	62.4	41.8
43.3	95.6	82.7	61.7	40.8
42.8	95.1	82.4	61	39.8
42.3	94.5	82.1	60.4	38.7
41.8	93.9	81.8	59.7	37.7
41.4	93.4	81.4	59	36.7
40.9	92.8	81.1	58.4	35.7
40.4	92.2	80.8	57.7	34.7
40	91.7	80.5	57	33.7
39.5	91.1	80.1	56.4	32.7

Approximate Hardness Conversion Numbers for Non-Austenitic Steels

Rockwell Hardness Number C Scale, 150 Kgf (HRC)	Vicker’s Hardness Number (HV)	Brinell Hardness No. 10mm Standard Ball, 3000 Kgf (HBS)	Brinell Hardness No. 10mm Carbide Ball, 3000 Kgf (HBW)	Knoop Hardness Number 500 gf & Over (HK)
68	940	…	…	920
67	900	…	…	895
66	865	…	…	870
65	832	…	…	846
64	800	…	…	822
63	772	…	…	799
62	746	…	…	776
61	720	…	…	754
60	697	…	…	732
59	674	…	634	710
58	653	…	615	690
57	633	…	595	670
56	613	…	577	650
55	595	…	560	630
54	577	…	543	612
53	560	…	525	594
52	544	…	512	576
51	528	…	496	558
50	513	…	481	542
49	498	…	469	526
48	484	451	455	510
47	471	442	443	495
46	458	432	432	480
45	446	421	421	466
44	434	409	409	452
43	423	400	400	438
42	412	390	390	426
41	402	381	381	414
40	392	371	371	402
39	382	362	362	391
38	372	353	353	380
37	363	344	344	370
36	354	336	336	360
35	345	327	327	351
34	336	319	319	342
33	327	311	311	334
32	318	301	301	326
31	310	294	294	318
30	302	286	286	311
29	294	279	279	304
28	286	271	271	297
27	279	264	264	290
26	272	258	258	284
25	266	253	253	278
24	260	247	247	272
23	254	243	243	266
22	248	237	237	261
21	243	231	231	256
20	238	226	226	251

Rockwell Hardness Number A Scale, 60 Kgf (HRA)	Rockwell Hardness Number D Scale, 100 Kgf (HRD)	Rockwell Superficial Hardness No. 15N Scale, 15 Kgf (15N)	Rockwell Superficial Hardness No. 30N Scale, 30 Kgf (30N)	Rockwell Superficial Hardness No. 45N Scale, 45 Kgf (45N)
85.6	76.9	93.2	84.4	75.4
85	76.1	92.9	83.6	74.2
84.5	75.4	92.5	82.8	73.3
83.9	74.5	92.2	81.9	72
83.4	73.8	91.8	81.1	71
82.8	73	91.4	80.1	69.9
82.3	72.2	91.1	79.3	68.8
81.8	71.5	90.7	78.4	67.7
81.2	70.7	90.2	77.5	66.6
80.7	69.9	89.8	76.6	65.5
80.1	69.2	89.3	75.7	64.3
79.6	68.5	88.9	74.8	63.2
79	67.7	88.3	73.9	62
78.5	66.9	87.9	73	60.9
78	66.1	87.4	72	59.8
77.4	65.4	86.9	71.2	58.6
76.8	64.6	86.4	70.2	57.4
76.3	63.8	85.9	69.4	56.1
75.9	63.1	85.5	68.5	55
75.2	62.1	85	67.6	53.8
74.7	61.4	84.5	66.7	52.5
74.1	60.8	83.9	65.8	51.4
73.6	60	83.5	64.8	50.3
73.1	59.2	83	64	49
72.5	58.5	82.5	63.1	47.8
72	57.7	82	62.2	46.7
71.5	56.9	81.5	61.3	45.5
70.9	56.2	80.9	60.4	44.3
70.4	55.4	80.4	59.5	43.1
69.9	54.6	79.9	58.6	41.9
69.4	53.8	79.4	57.7	40.8
68.9	53.1	78.8	56.8	39.6
68.4	52.3	78.3	55.9	38.4
67.9	51.5	77.7	55	37.2
67.4	50.8	77.2	54.2	36.1
66.8	50	76.6	53.3	34.9
66.3	49.2	76.1	52.1	33.7
65.8	48.4	75.6	51.3	32.5
65.3	47.7	75	50.4	31.3
64.8	47	74.5	49.5	30.1
64.3	46.1	73.9	48.6	28.9
63.8	45.2	73.3	47.7	27.8
63.3	44.6	72.8	46.8	26.7
62.8	43.8	72.2	45.9	25.5
62.4	43.1	71.6	45	24.3
62	42.1	71	44	23.1
61.5	41.6	70.5	43.2	22
61	40.9	69.9	42.3	20.7
60.5	40.1	69.4	41.5	19.6

Approximate Hardness Conversion No.s for Cartridge Brass (70&perc Cu 30% Zn Alloy)

Approximate Hardness Conversion Numbers for Nickel & High-Nickel Alloys

Approximate Hardness Conversion No.’s for Austenitic Stainless Steel Sheet

Approximate Hardness Conversion No.’s for Austenitic Stainless Steel Sheet

Approximate Hardness Conversion Numbers for Non-Austenitic Steels

Approximate Hardness Conversion Numbers for Non-Austenitic Steels

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Rockwell B Hardness No. 100 Kgf (HRB)	Vicker’s Hardness Number (HV)	Brinell Hardness No. 10mm Standard Ball, 3000 Kgf (HBS)	Knoop Hardness Number 500 gf & Over (HK)
100	240	240	251
99	234	234	246
98	228	228	241
97	222	222	236
96	216	216	231
95	210	210	226
94	205	205	221
93	200	200	216
92	195	195	211
91	190	190	206
90	185	185	201
89	180	180	196
88	176	176	192
87	172	172	188
86	169	169	184
85	165	165	180
84	162	162	176
83	159	159	173
82	156	156	170
81	153	153	167
80	150	150	164
79	147	147	161
78	144	144	158
77	141	141	155
76	139	139	152
75	137	137	150
74	135	135	147
73	132	132	145
72	130	130	143
71	127	127	141
70	125	125	139
69	123	123	137
68	121	121	135
67	119	119	133
66	117	117	131
65	116	116	129
64	114	114	127
63	112	112	125
62	110	110	124
61	108	108	122
60	107	107	120

Rockwell Hardness Number C Scale, 150 Kgf (HRC)	Vicker’s Hardness Number (HV)	Brinell Hardness No. 10mm Standard Ball, 3000 Kgf (HBS)	Brinell Hardness No. 10mm Carbide Ball, 3000 Kgf (HBW)	Knoop Hardness Number 500 gf & Over (HK)
68	940	…	…	920
67	900	…	…	895
66	865	…	…	870
65	832	…	…	846
64	800	…	…	822
63	772	…	…	799
62	746	…	…	776
61	720	…	…	754
60	697	…	…	732
59	674	…	634	710
58	653	…	615	690
57	633	…	595	670
56	613	…	577	650
55	595	…	560	630
54	577	…	543	612
53	560	…	525	594
52	544	…	512	576
51	528	…	496	558
50	513	…	481	542
49	498	…	469	526
48	484	451	455	510
47	471	442	443	495
46	458	432	432	480
45	446	421	421	466
44	434	409	409	452
43	423	400	400	438
42	412	390	390	426
41	402	381	381	414
40	392	371	371	402
39	382	362	362	391
38	372	353	353	380
37	363	344	344	370
36	354	336	336	360
35	345	327	327	351
34	336	319	319	342
33	327	311	311	334
32	318	301	301	326
31	310	294	294	318
30	302	286	286	311
29	294	279	279	304
28	286	271	271	297
27	279	264	264	290
26	272	258	258	284
25	266	253	253	278
24	260	247	247	272
23	254	243	243	266
22	248	237	237	261
21	243	231	231	256
20	238	226	226	251

Rockwell B Hardness No. 100 Kgf (HRB)	Vicker’s Hardness Number (HV)	Brinell Hardness No. 10mm Standard Ball, 3000 Kgf (HBS)	Knoop Hardness Number 500 gf & Over (HK)
100	240	240	251
99	234	234	246
98	228	228	241
97	222	222	236
96	216	216	231
95	210	210	226
94	205	205	221
93	200	200	216
92	195	195	211
91	190	190	206
90	185	185	201
89	180	180	196
88	176	176	192
87	172	172	188
86	169	169	184
85	165	165	180
84	162	162	176
83	159	159	173
82	156	156	170
81	153	153	167
80	150	150	164
79	147	147	161
78	144	144	158
77	141	141	155
76	139	139	152
75	137	137	150
74	135	135	147
73	132	132	145
72	130	130	143
71	127	127	141
70	125	125	139
69	123	123	137
68	121	121	135
67	119	119	133
66	117	117	131
65	116	116	129
64	114	114	127
63	112	112	125
62	110	110	124
61	108	108	122
60	107	107	120

Rockwell Hardness Number C Scale, 150 Kgf (HRC)	Vicker’s Hardness Number (HV)	Brinell Hardness No. 10mm Standard Ball, 3000 Kgf (HBS)	Brinell Hardness No. 10mm Carbide Ball, 3000 Kgf (HBW)	Knoop Hardness Number 500 gf & Over (HK)
68	940	…	…	920
67	900	…	…	895
66	865	…	…	870
65	832	…	…	846
64	800	…	…	822
63	772	…	…	799
62	746	…	…	776
61	720	…	…	754
60	697	…	…	732
59	674	…	634	710
58	653	…	615	690
57	633	…	595	670
56	613	…	577	650
55	595	…	560	630
54	577	…	543	612
53	560	…	525	594
52	544	…	512	576
51	528	…	496	558
50	513	…	481	542
49	498	…	469	526
48	484	451	455	510
47	471	442	443	495
46	458	432	432	480
45	446	421	421	466
44	434	409	409	452
43	423	400	400	438
42	412	390	390	426
41	402	381	381	414
40	392	371	371	402
39	382	362	362	391
38	372	353	353	380
37	363	344	344	370
36	354	336	336	360
35	345	327	327	351
34	336	319	319	342
33	327	311	311	334
32	318	301	301	326
31	310	294	294	318
30	302	286	286	311
29	294	279	279	304
28	286	271	271	297
27	279	264	264	290
26	272	258	258	284
25	266	253	253	278
24	260	247	247	272
23	254	243	243	266
22	248	237	237	261
21	243	231	231	256
20	238	226	226	251

Rockwell B Hardness No. 100 Kgf (HRB)	Vicker’s Hardness Number (HV)	Brinell Hardness No. 10mm Standard Ball, 3000 Kgf (HBS)	Knoop Hardness Number 500 gf & Over (HK)
100	240	240	251
99	234	234	246
98	228	228	241
97	222	222	236
96	216	216	231
95	210	210	226
94	205	205	221
93	200	200	216
92	195	195	211
91	190	190	206
90	185	185	201
89	180	180	196
88	176	176	192
87	172	172	188
86	169	169	184
85	165	165	180
84	162	162	176
83	159	159	173
82	156	156	170
81	153	153	167
80	150	150	164
79	147	147	161
78	144	144	158
77	141	141	155
76	139	139	152
75	137	137	150
74	135	135	147
73	132	132	145
72	130	130	143
71	127	127	141
70	125	125	139
69	123	123	137
68	121	121	135
67	119	119	133
66	117	117	131
65	116	116	129
64	114	114	127
63	112	112	125
62	110	110	124
61	108	108	122
60	107	107	120

Rockwell Hardness Number C Scale, 150 Kgf (HRC)	Vicker’s Hardness Number (HV)	Brinell Hardness No. 10mm Standard Ball, 3000 Kgf (HBS)	Brinell Hardness No. 10mm Carbide Ball, 3000 Kgf (HBW)	Knoop Hardness Number 500 gf & Over (HK)
68	940	…	…	920
67	900	…	…	895
66	865	…	…	870
65	832	…	…	846
64	800	…	…	822
63	772	…	…	799
62	746	…	…	776
61	720	…	…	754
60	697	…	…	732
59	674	…	634	710
58	653	…	615	690
57	633	…	595	670
56	613	…	577	650
55	595	…	560	630
54	577	…	543	612
53	560	…	525	594
52	544	…	512	576
51	528	…	496	558
50	513	…	481	542
49	498	…	469	526
48	484	451	455	510
47	471	442	443	495
46	458	432	432	480
45	446	421	421	466
44	434	409	409	452
43	423	400	400	438
42	412	390	390	426
41	402	381	381	414
40	392	371	371	402
39	382	362	362	391
38	372	353	353	380
37	363	344	344	370
36	354	336	336	360
35	345	327	327	351
34	336	319	319	342
33	327	311	311	334
32	318	301	301	326
31	310	294	294	318
30	302	286	286	311
29	294	279	279	304
28	286	271	271	297
27	279	264	264	290
26	272	258	258	284
25	266	253	253	278
24	260	247	247	272
23	254	243	243	266
22	248	237	237	261
21	243	231	231	256
20	238	226	226	251