Hardness Conversion Table

Hardness Conversion Table ASTM

Rockwell C Hardness Range

Approximate Hardness Conversion Numbers for Non-Austenitic Steels, According to ASTM E-140 The Conversion Values contained herein should be considered approximate only and may be inaccurate for specific applications

C	A	D	15N	30N	45N	Vickers	Brinell	Tensile
150 kgf	60 kgf	100 kgf	15 kgf	30 kgf	45 kgf	Hardness	Hardness	Strength
diamond	diamond	diamond	diamond	diamond	diamond		3000 kgf 10mm ball	1000 lbs/square in
68	85.6	76.9	93.2	84.4	75.4	940	..	..
67	85.0	76.1	92.9	83.6	74.2	900	..	..
66	84.5	75.4	92.5	82.8	73.3	865	..	..
65	83.9	74.5	92.2	81.9	72.0	832	(739)
64	83.4	73.8	91.8	81.1	71.0	800	(722)
63	82.8	73.0	91.4	80.1	69.9	772	(705)
62	82.3	72.2	91.1	79.3	68.8	745	(688)
61	81.8	71.5	90.7	78.4	67.7	720	(670)
60	81.2	70.7	90.2	77.5	66.6	697	(654)
59	80.7	69.9	89.8	76.6	65.5	674	(634)	351
58	80.1	69.2	89.3	75.7	64.3	653	615	338
57	79.6	68.5	88.9	74.8	63.2	633	595	325
56	79.0	67.7	88.3	73.9	62.0	613	577	313
55	78.5	66.9	87.9	73.0	60.9	595	560	301
54	78.0	66.1	87.4	72.0	59.8	577	543	292
53	77.4	65.4	86.9	71.2	58.6	560	525	283
52	76.8	64.6	84.4	70.2	57.4	544	512	273
51	76.3	63.8	85.9	69.4	56.1	528	496	264
50	75.9	63.1	85.5	68.5	55.0	513	481	255
49	75.2	62.1	85.0	67.6	53.8	498	469	246
48	74.7	61.4	84.6	66.7	52.5	484	455	237
47	74.1	60.8	83.9	65.8	51.4	471	443	229
46	73.6	60.0	83.5	64.8	50.3	458	432	221
45	73.1	59.2	83.0	64.0	49.0	446	421	215
44	72.5	58.5	82.5	63.1	47.8	434	409	208
43	72.0	57.7	82.0	62.2	46.7	423	400	201
42	71.5	56.9	81.5	61.3	45.5	412	390	195
41	70.9	56.2	80.9	60.4	44.3	402	381	188
40	70.4	55.4	80.4	59.5	43.1	392	371	182
39	69.9	54.6	79.9	58.6	41.9	382	362	177
38	69.4	53.8	79.4	57.7	40.8	372	353	171
37	58.9	53.1	78.8	56.8	39.6	363	344	166
36	68.4	52.3	78.3	55.9	38.4	354	336	161
35	67.9	51.5	77.7	55.0	37.2	345	327	156
34	67.4	50.8	77.2	54.2	36.1	336	319	152
33	66.8	50.0	76.6	53.3	34.9	327	311	149
32	66.3	49.2	76.1	52.1	33.7	318	301	146
31	65.8	48.4	75.6	51.3	32.5	310	294	141
30	65.3	47.7	75.0	50.4	31.3	302	286	138
29	64.8	47.0	74.5	49.5	30.1	294	279	135
28	64.3	46.1	73.9	48.6	28.9	286	271	131
27	63.8	45.2	73.3	47.7	27.8	279	264	128
26	63.3	44.6	72.8	46.8	26.7	272	258	125
25	62.8	43.8	72.2	45.9	25.5	266	253	123
24	62.4	43.1	71.6	45.0	24.3	260	247	119
23	62.0	42.1	71.0	44.0	23.1	254	243	117
22	61.5	41.6	70.5	43.2	22.0	248	237	115
21	61.0	40.9	69.9	42.3	20.7	243	231	112
20	60.5	40.1	69.4	41.5	19.6	238	226	110

Rockwell B Hardness Range

Approximate Hardness Conversion Numbers for Non-Austenitic Steels, according to ASTM E-140 The conversion values contained herein should be considered approximate only and may be inaccurate for specific applications.

Rockwell			Superficial Rockwell			Vickers	Brinell	Tensile	Brinelll
B	A	E	15T	30T	45T	Hardness	Hardness	Strength	Hardness
100 kgf	60 kgf	100 kgf	15 kgf	30 kgf	45 kgf		3000 kgf	1000 lbs/	500 kgf
1/16″ ball	diamond	1/8″ ball	1/16″ ball	1/16″ ball	1/16″ ball		10mm ball	square in	10mm ball
100	61.5		93.1	83.1	72.9	240	240	116	201
99	60.9		82.8	82.5	71.9	234	234	114	195
98	60.2		92.5	81.8	70.9	228	228	109	189
97	59.5		92.1	81.1	69.9	222	222	105	184
96	58.9		91.8	80.4	68.9	216	216	102	179
95	58.3		91.5	79.8	67.9	210	210	100	175
94	57.6		91.2	79.1	66.9	205	205	98	171
93	57.0		90.8	78.4	65.9	200	200	94	167
92	56.4		90.5	77.8	64.8	195	195	92	163
91	55.8		90.2	77.1	63.8	190	190	90	160
90	55.2		89.9	76.4	62.8	186	186	89	157
89	54.6		89.5	76.8	61.8	180	180	88	164
88	64.0		89.2	75.1	60.8	176	176	86	151
87	53.4		88.9	74.4	59.8	172	172	84	148
86	52.8		88.6	73.8	58.8	169	169	83	145
85	52.3		88.2	73.1	57.8	165	165	82	142
84	51.7		87.9	72.4	56.8	162	162	81	140
83	51.1		87.6	71.8	55.8	159	159	80	137
82	50.6		87.3	71.1	54.8	156	156	76	135
81	50.0		86.9	70.4	53.8	153	153	73	133
80	49.5		86.6	69.7	52.8	150	150	72	130
79	48.9		86.3	69.1	51.8	147	147	70	128
78	48.4		86.0	68.4	50.8	144	144	69	126
77	47.9		85.6	67.7	49.8	141	141	68	124
76	47.3		85.3	67.1	48.8	139	139	67	122
75	46.8		86.0	66.4	47.8	137	137	66	120
74	46.3		84.7	65.7	46.8	135	135	66	118
73	45.8		84.3	65.1	45.8	132	132	64	116
72	45.3		84.0	64.4	44.8	130	130	63	114
71	44.8	100.0	83.7	63.7	43.8	127	127	62	112
70	44.3	99.5	83.4	63.1	42.8	125	125	61	110
69	43.8	99.0	83.0	62.4	41.8	123	123	60	109
68	43.3	98.0	82.7	61.7	40.8	121	121	59	108
67	42.8	97.5	82.4	61.0	39.8	119	119	58	106
66	42.3	97.0	82.1	60.4	38.7	117	117	57	104
65	41.8	96.0	81.8	59.7	37.7	116	116	56	102
64	41.4	95.5	81.4	59.0	36.7	114	114		100
63	40.9	95.0	81.1	58.4	35.7	112	112		99
62	40.4	94.5	80.8	57.7	34.7	110	110		98
61	40.0	93.5	80.5	57.0	33.7	108	108		96
60	39.5	93.0	80.1	56.4	32.7	107	107		95
59	39.0	92.5	79.8	55.7	31.7	106	106		94
58	38.6	92.0	79.5	55.0	30.7	104	104		92
57	38.1	91.0	79.2	54.4	3.0	103	103		91
56	37.7	90.6	78.8	53.7	28.7	101	101		90
55	37.2	90.0	78.6	53.0	27.7	100	100		89
54	36.8	89.5	78.2	52.4	26.7				87
53	36.3	89.0	77.9	51.7	26.7				86
52	35.9	88.0	77.5	51.0	24.7				85
51	35.5	87.6	77.2	50.3	23.7				84
50	35.0	87.0	76.9	49.7	22.7				83
49	34.6	86.5	76.6	49.0	21.7				82
48	34.1	85.5	76.2	48.3	20.7				81
47	33.7	85.0	75.9	47.7	19.7				80
46	33.3	84.6	76.6	47.0	18.7				80
45	32.9	84.0	76.3	46.3	17.7				79
44	32.4	83.5	74.9	45.7	16.7				78
43	32.0	82.5	74.6	45.0	15.7				77
42	31.6	82.0	74.3	44.3	14.7				76
41	31.2	81.5	74.0	43.7	13.6				75
40	30.7	81.0	73.6	43.0	12.6				75
39	30.3	80.0	73.3	42.3	11.6				74
38	29.9	79.5	73.0	41.6	10.6				73
37	29.5	79.0	72.7	41.0	9.6				72
36	29.1	78.5	72.3	40.3	8.6				72
35	28.7	78.0	72.0	39.6	7.6				71
34	28.2	77.0	71.7	39.0	6.6				70
33	27.8	76.6	71.4	38.3	5.6				69
32	27.4	76.0	71.0	37.6	4.6				69
31	27.0	75.5	70.7	37.0	3.6				68
30	26.6	75.0	70.4	36.3	2.6				67

Hardness values in brackets are outside the range recommended for Brinell testing in ASTM E-10. The above table is from ASTM E-110 except values for E-scale and Tensile Strength which are not from or according to ASTM Standards. Reprinted from the Annual Book of ASTM Standards, copyright American Society for Testing and Materials.

Hardness Conversion Table