HARDNESS CONVERSION TABLE
...
BRINELL HARDNESS
ROCKWELL B SCALE
ROCKWELL C SCALE
APPROX. TENSILE LBS. P.S.I.
653
...
62
324,000
627
...
60
311,000
601
...
59
306,000
578
...
57
290,000
555
...
56
284,000
534
...
54
270,000
514
...
53
263,000
495
...
51
250,000
477
...
50
243,000
461
...
49
236,000
444
...
47
223,000
429
...
46
217,000
415
...
45
211,000
401
...
42
194,000
388
...
41
188,000
375
...
40
182,000
363
...
38
171,000
352
...
37
166,000
331
...
36
162,000
321
34
153,000
311
...
33
148,000
302
...
32
144,000
293
...
31
140,000
285
...
30
136,000
277
...
29
132,000
269
...
28
129,000
262
...
27
126,000
255
...
25
120.000
248
...
24
117,000
241
100
23
115,000
235
99
22
112,000
229
98
21
110,000
223
97
20
108,000
217
96
...
103,000
212
96
...
103,000
207
95
...
101,000
202
94
...
98,000
197
93
...
96,000
192
92
...
93,000
187
91
...
91,000
183
90
...
89,00
179
89
...
87,000
174
88
...
85,000
170
87
...
83,000
166
86
...
81,000
163
85
...
80,000
159
84
...
78,000
156
83
...
77,000
153
82
...
76,000
149
81
...
75,000
146
80
...
74,000
143
79
...
73,000
140
78
...
71,000
137
77
...
70,000
134
76
...
69,000
131
74
...
67,000
128
73
...
66,000
126
72
...
65,000
124
71
...
63,000
121
70
...
62,000
118
69
...
61,000
116
68
...
60,000
114
67
...
59,000
112
66
...
58,000
109
65
...
57,000
107
64
...
55,000
105
62
...
54,000
...
* The tolerances for flats apply to thickness as well as width.