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Hardness Conversion Table

Approximate Relation of Brinell And Rockwell Hardness To Tensile Strength
For Carbon And Alloy Steel

Brinell Indent Dia. mm.	Brinell 10-mm. Ball, 3000-kg. Load	Rockwell Hardness Number		Tensile Strength (Approx.) 1000 psi	Brinell Indent Dia. mm.	Brinell 10-mm. Ball, 3000-kg. Load	Rockwell Hardness Number		Tensile Strength (Approx.) 1000 psi
Brinell Indent Dia. mm.	Hardness Number	B-Scale 100-kg. Load ¹/₁₆" Diam. Ball	C-Scale 150kg. Load Brale Penetrator	Tensile Strength (Approx.) 1000 psi	Brinell Indent Dia. mm.	Hardness Number	B-Scale 100-kg. Load ¹/₁₆" Diam. Ball	C-Scale 150kg. Load Brale Penetrator	Tensile Strength (Approx.) 1000 psi
-	-	-	68.0	-	3.00	415	-	44.5	210
-	-	-	67.5	-	3.05	401	-	43.1	202
-	-	-	67.0	-	3.10	388	-	41.8	195
-	767	-	66.4	-	3.15	375	-	40.4	188
-	757	-	65.9	-	3.20	363	-	39.1	182
2.25	745	-	65.3	-	3.25	352	(110.0)	37.9	1.76
-	733	-	64.7	-	3.30	341	(109.0)	36.6	170
-	722	-	64.0	-	3.35	331	(108.5)	35.5	166
2.30	712	-	-	-	3.40	321	(108.0)	34.3	160
-	710	-	63.3	-	3.45	311	(107.5)	33.1	155
-	698	-	62.5	-	3.50	302	(107.0)	32.1	150
-	684	-	61.8	-	3.55	293	(106.0)	30.9	145
2.35	682	-	61.7	-	3.60	285	(105.5)	29.9	141
-	670	-	61.0	-	3.65	277	(105.5)	28.8	137
-	656	-	60.1	-	3.70	269	(104.0)	27.6	133
2.40	653	-	59.7	-	3.75	262	(103.0)	26.6	129
-	647	-	59.7	-	3.80	255	(102.0)	25.4	126
-	638	-	59.2	329	3.85	248	(101.0)	24.2	122
-	630	-	58.8	324	3.90	241	100.0	22.8	118
2.45	627	-	58.7	323	3.95	235	99.0	21.7	115
2.50	601	-	59.1	328	4.00	229	98.2	20.5	111
-	601	-	57.3	309	4.05	223	973	(18.8)	-
2.55	578	-	57.3	309	4.10	217	96.4	(17.5)	105
-	578	-	56.0	297	4.15	212	95.5	(16.0)	102
2.60	555	-	55.6	293	4.20	207	94.6	(15.2)	100
2.60	555	-	54.7	285	4.25	201	93.8	(13.8)	98
2.65	534	-	54.0	279	4.30	197	92.8	(12.7)	95
-	534	-	53.5	274	4.35	192	91.9	(11.5)	93
2.70	514	-	52.5	265	4.40	187	90.7	(10.0)	90
-	514	-	52.1	263	4.45	183	90.0	(9.0)	89
2.75	495	-	51.6	259	4.50	179	89.0	(8.0)	87
-	495	-	51.1	254	4.55	174	87.8	(6.4)	85
-	495	-	51.0	253	4.60	170	86.8	(5.4)	83
2.80	477	-	50.3	247	4.65	167	86.0	(4.4)	81
-	477	-	49.6	243	4.70	163	85.0	(3.3)	79
2.80	477	-	49.6	243	4.80	156	82.9	(0.9)	76
2.85	461	-	48.8	237	4.90	149	80.8	-	73
-	461	-	48.5	235	5.00	143	78.7	-	71
2.85	461	-	48.5	235	5.10	137	76.4	-	67
2.90	444	-	47.2	226	5.20	131	74.0	-	65
-	444	-	47.1	225	5.30	126	72.0	-	63
-	444	-	47.1	225	5.40	121	69.8	-	60
2.95	429	-	45.7	217	5.50	116	67.6	-	58
-	429	-	45.7	217	5.60	111	65.7	-	56
Values for Rockwell hardness in parentheses are beyond normal range, and are given for information only. Brinell hardness No.'s 767 through 514 based on tests taken with tungsten carbide ball.

The information and data presented herein are typical or average values and are not a guarantee of maximum or minimum values. Applications specifically suggested for material described herein are made solely for the purpose of illustration to enable the reader to make his own evaluation and are not intended as warranties, either express or implied, of fitness for these or other purposes.