Comparative Hardness Scales for Steel Table

Engineering Materials

Comparison of Hardness Scales: The following table compares the various hardness scales. Assumptions are that the metal tested is homogeneous to a depth several times that of the indentation. To the extent that the metal being tested is not homogeneous, errors are introduced because different loads and different shapes of penetrators meet the resistance of metal of varying hardness, depending on the depth of indentation. Another source of error is introduced in comparing the hardness of different materials as measured on different hardness scales. This error arises from the fact that in any hardness test, metal that is severely cold-worked actually supports the penetrator, and different metals, different alloys, and different analyses of the same type of alloy have different cold-working properties.

Rockwell C-Scal eHardness Number	Diamond Pyramid Hardness Number Vickers	Brinell Hardness Number 10-mm Ball, 3000-kgf Load			Rockwell Hardness Number		Rockwell Superficial Hardness Number Superficial Diamond Indenter			Shore Scleroscope Hardness Number
Rockwell C-Scal eHardness Number	Diamond Pyramid Hardness Number Vickers	Standard Ball	Hultgren Ball	Tungsten Carbide Ball	A-Scale 60-kgf Load Diamond Indenter	D-Scale 100-kgf Load Diamond Indenter	15-N Scale 15-kgf Load	30-N Scale 30kgf Load	45-N Scale 45-kgf Load	Shore Scleroscope Hardness Number
68	940	…	…	…	85.6	76.9	93.2	84.4	75.4	97
67	900	…	…	…	85.0	76.1	92.9	83.6	74.2	95
66	865	…	…	…	84.5	75.4	92.5	82.8	73.3	92
65	832	…	…	(739)	83.9	74.5	92.2	81.9	72.0	91
64	800	…	…	(722)	83.4	73.8	91.8	81.1	71.0	88
63	772	…	…	(705)	82.8	73.0	91.4	80.1	69.9	87
62	746	…	…	(688)	82.3	72.2	91.1	79.3	68.8	85
61	720	…	…	(670)	81.8	71.5	90.7	78.4	67.7	83
60	697	…	(613)	(654)	81.2	70.7	90.2	77.5	66.6	81
59	674	…	(599)	(634)	80.7	69.9	89.8	76.6	65.5	80
58	653	…	(587)	615	80.1	69.2	89.3	75.7	64.3	78
57	633	…	(575)	595	79.6	68.5	88.9	74.8	63.2	76
56	613	…	(561)	577	79.0	67.7	88.3	73.9	62.0	75
55	595	…	(546)	560	78.5	66.9	87.9	73.0	60.9	74
54	577	…	(534)	543	78.0	66.1	87.4	72.0	59.8	72
53	560	…	(519)	525	77.4	65.4	86.9	71.2	58.6	71
52	544	(500)	(508)	512	76.8	64.6	86.4	70.2	57.4	69
51	528	(487)	(494)	496	76.3	63.8	85.9	69.4	56.1	68
50	513	(475)	(481)	481	75.9	63.1	85.5	68.5	55.0	67
49	498	(464)	(469)	469	75.2	62.1	85.0	67.6	53.8	66
48	484	(451)	(455)	455	74.7	61.4	84.5	66.7	52.5	64
47	471	442	443	443	74.1	60.8	83.9	65.8	51.4	63
46	458	432	432	432	73.6	60.0	83.5	64.8	50.3	62
45	446	421	421	421	73.1	59.2	83.0	64.0	49.0	60
44	434	409	409	409	72.5	58.5	82.5	63.1	47.8	58
43	423	400	400	400	72.0	57.7	82.0	62.2	46.7	57
42	412	390	390	390	71.5	56.9	81.5	61.3	45.5	56
41	402	381	381	381	70.9	56.2	80.9	60.4	44.3	55
40	392	371	371	371	70.4	55.4	80.4	59.5	43.1	54
39	382	362	362	362	69.9	54.6	79.9	58.6	41.9	52
38	372	353	353	353	69.4	53.8	79.4	57.7	40.8	51
37	363	344	344	344	68.9	53.1	78.8	56.8	39.6	50
36	354	336	336	336	68.4	52.3	78.3	55.9	38.4	49
35	345	327	327	327	67.9	51.5	77.7	55.0	37.2	48
34	336	319	319	319	67.4	50.8	77.2	54.2	36.1	47
33	327	311	311	311	66.8	50.0	76.6	53.3	34.9	46
32	318	301	301	301	66.3	49.2	76.1	52.1	33.7	44
31	310	294	294	294	65.8	48.4	75.6	51.3	32.5	43
30	302	286	286	286	65.3	47.7	75.0	50.4	31.3	42
29	294	279	279	279	64.7	47.0	74.5	49.5	30.1	41
28	286	271	271	271	64.3	46.1	73.9	48.6	28.9	41
27	279	264	264	264	63.8	45.2	73.3	47.7	27.8	40
26	272	258	258	258	63.3	44.6	72.8	46.8	26.7	38
25	266	253	253	253	62.8	43.8	72.2	45.9	25.5	38
24	260	247	247	247	62.4	43.1	71.6	45.0	24.3	37
23	254	243	243	243	62.0	42.1	71.0	44.0	23.1	36
22	248	237	237	237	61.5	41.6	70.5	43.2	22.0	35
21	243	231	231	231	61.0	40.9	69.9	42.3	20.7	35
20	238	226	226	226	60.5	40.1	69.4	41.5	19.6	34
(18)	230	219	219	219	…	…	…	…	…	33
(16)	222	212	212	212	…	…	…	…	…	32
(14)	213	203	203	203	…	…	…	…	…	31
(12)	204	194	194	194	…	…	…	…	…	29
(10)	196	187	187	187	…	…	…	…	…	28
(8)	188	179	179	179	…	…	…	…	…	27
(6)	180	171	171	171	…	…	…	…	…	26
(4)	173	165	165	165	…	…	…	…	…	25
(2)	166	158	158	158	…	…	…	…	…	24
(0)	160	152	152	152	…	…	…	…	…	24