Hardness conversion: Rockwell, Brinell, Vickers

Convert hardness scales for steels: Rockwell C and B (HRC, HRB), Vickers (HV), Brinell (HB) and estimated tensile strength. With a full conversion chart.

From scale

Value

Rockwell C

–HRC

Rockwell B

–HRB

Vickers

–HV

Brinell

–HB

Estimated tensile strength

–MPa

How it works

There is no exact physical relationship between hardness scales, so conversions rely on empirical tables. The values here follow ASTM E140 for non-austenitic carbon and low-alloy steels, with linear interpolation between table points.

Formula

ASTM E140 / ISO 18265 (steel), linear interpolation
Rm ≈ 3.2 × HV

Rockwell C is not used below about 20 HRC and Rockwell B not above 100 HRB, so no result is given outside these ranges. Tensile strength (Rm ≈ 3.2 × HV) is only a rough estimate. Austenitic steels, cast iron and non-ferrous metals need other tables.

Chart

HRC	HRB	HV	HB	Rm ≈ MPa
68	–	940	–	3,010
67	–	900	–	2,880
66	–	865	–	2,770
65	–	832	739	2,660
64	–	800	722	2,560
63	–	772	706	2,470
62	–	746	688	2,385
61	–	720	670	2,305
60	–	697	654	2,230
59	–	674	634	2,155
58	–	653	615	2,090
57	–	633	595	2,025
56	–	613	577	1,960
55	–	595	560	1,905
54	–	577	543	1,845
53	–	560	525	1,790
52	–	544	512	1,740
51	–	528	496	1,690
50	–	513	481	1,640
49	–	498	469	1,595
48	–	484	455	1,550
47	–	471	443	1,505
46	–	458	432	1,465
45	–	446	421	1,425
44	–	434	409	1,390
43	–	423	400	1,355
42	–	412	390	1,320
41	–	402	381	1,285
40	–	392	371	1,255
39	–	382	362	1,220
38	–	372	353	1,190
37	–	363	344	1,160
36	–	354	336	1,135
35	–	345	327	1,105
34	–	336	319	1,075
33	–	327	311	1,045
32	–	318	301	1,020
31	–	310	294	990
30	–	302	286	965
29	–	294	279	940
28	–	286	271	915
27	–	279	264	895
26	–	272	258	870
25	–	266	253	850
24	–	260	247	830
23	–	254	243	815
22	–	248	237	795
21	–	243	231	780
20	–	238	226	760
–	99	234	234	750
–	98	228	228	730
–	97	222	222	710
–	96	216	216	690
–	95	210	210	670
–	94	205	205	655
–	93	200	200	640
–	92	195	195	625
–	91	190	190	610
–	90	185	185	590
–	89	180	180	575
–	88	176	176	565
–	87	172	172	550
–	86	169	169	540
–	85	165	165	530
–	84	162	162	520
–	83	159	159	510
–	82	156	156	500
–	81	153	153	490
–	80	150	150	480
–	79	147	147	470
–	78	144	144	460
–	77	141	141	450
–	76	139	139	445
–	75	137	137	440
–	74	135	135	430
–	73	132	132	420
–	72	130	130	415
–	71	127	127	405
–	70	125	125	400
–	69	123	123	395
–	68	121	121	385
–	67	119	119	380
–	66	117	117	375
–	65	116	116	370
–	64	114	114	365
–	63	112	112	360
–	62	110	110	350
–	61	108	108	345
–	60	107	107	340

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