Hardness Conversions
Brinell Indentation Diameter
mm
|
Brinell Hardness Number
|
Rockwell Hardness Number
|
Rockwell Superficial Hardness
Number Superficial Diamond Penetrator
|
Tensile Strength (approx.)
1000 p.s.
|
||||
Standard Ball
|
Tungsten- Carbide Ball
|
B Scale
|
C Scale
|
15N Scale
|
30N Scale
|
45N Scale
|
||
2.45
|
|
627
|
58.70
|
89.60
|
76.30
|
65.10
|
|
347
|
2.50
|
|
601
|
|
57.30
|
89.00
|
75.10
|
63.50
|
328
|
2.55
|
|
578
|
|
56.00
|
88.40
|
73.90
|
62.10
|
313
|
2.60
|
|
555
|
|
54.70
|
87.80
|
72.70
|
60.60
|
298
|
2.65
|
|
534
|
|
53.50
|
87.20
|
71.60
|
59.20
|
288
|
2.70
|
|
514
|
|
52.10
|
86.50
|
70.30
|
57.60
|
274
|
2.75
|
|
495
|
|
51.00
|
85.90
|
69.40
|
56.10
|
264
|
2.80
|
|
477
|
|
49.60
|
85.30
|
68.20
|
54.50
|
252
|
2.85
|
|
461
|
|
48.50
|
84.70
|
67.20
|
53.20
|
242
|
2.90
|
|
444
|
|
47.10
|
84.00
|
65.80
|
51.50
|
230
|
2.95
|
429
|
429
|
|
45.70
|
83.40
|
64.60
|
49.90
|
219
|
3.00
|
415
|
415
|
|
44.50
|
82.80
|
63.50
|
48.40
|
212
|
3.05
|
401
|
401
|
|
43.10
|
82.00
|
62.30
|
46.90
|
202
|
3.10
|
388
|
388
|
|
41.80
|
81.40
|
61.10
|
45.30
|
193
|
3.15
|
375
|
375
|
|
40.40
|
80.60
|
59.90
|
43.60
|
184
|
3.20
|
363
|
363
|
|
39.10
|
80.00
|
58.70
|
42.00
|
177
|
3.25
|
352
|
352
|
|
37.90
|
79.30
|
57.60
|
40.50
|
170
|
3.30
|
341
|
341
|
|
36.60
|
78.60
|
56.40
|
39.10
|
163
|
3.35
|
331
|
331
|
|
35.50
|
78.00
|
55.40
|
37.80
|
158
|
3.40
|
321
|
321
|
|
34.30
|
77.30
|
54.30
|
36.40
|
152
|
3.45
|
311
|
311
|
|
33.10
|
76.70
|
53.30
|
34.40
|
147
|
3.50
|
302
|
302
|
|
32.10
|
76.10
|
52.20
|
33.80
|
143
|
3.55
|
293
|
293
|
|
30.90
|
75.50
|
51.20
|
32.40
|
139
|
3.60
|
285
|
285
|
|
29.90
|
75.00
|
50.30
|
31.20
|
136
|
3.65
|
277
|
277
|
|
28.80
|
74.40
|
49.30
|
29.90
|
131
|
3.70
|
269
|
269
|
|
27.60
|
73.70
|
48.30
|
28.50
|
128
|
3.75
|
262
|
262
|
|
26.60
|
73.10
|
47.30
|
27.30
|
125
|
3.80
|
255
|
255
|
|
25.40
|
72.50
|
46.20
|
26.00
|
121
|
3.85
|
248
|
248
|
|
24.20
|
71.70
|
45.10
|
24.50
|
118
|
3.90
|
241
|
241
|
100.00
|
22.80
|
70.90
|
43.90
|
22.80
|
114
|
3.95
|
235
|
235
|
99.00
|
21.70
|
70.00
|
42.90
|
21.50
|
111
|
4.00
|
229
|
229
|
98.20
|
20.50
|
69.70
|
41.90
|
20.10
|
109
|
4.05
|
223
|
223
|
97.30
|
|
|
|
|
104
|
4.10
|
217
|
217
|
63.40
|
|
|
|
|
103
|
4.15
|
212
|
212
|
95.50
|
|
|
|
|
100
|
4.20
|
207
|
207
|
94.60
|
|
|
|
|
99
|
4.25
|
201
|
201
|
93.80
|
|
|
|
|
97
|
4.30
|
197
|
197
|
92.80
|
|
|
|
|
94
|
4.35
|
192
|
192
|
91.90
|
|
|
|
|
92
|
4.40
|
187
|
187
|
90.70
|
|
|
|
|
90
|
4.45
|
183
|
183
|
90.00
|
|
|
|
|
89
|
4.50
|
179
|
179
|
89.00
|
|
|
|
|
88
|
4.55
|
174
|
174
|
87.80
|
|
|
|
|
86
|
4.60
|
170
|
170
|
86.80
|
|
|
|
|
84
|
4.65
|
167
|
167
|
86.00
|
|
|
|
|
83
|
4.70
|
163
|
163
|
85.00
|
|
|
|
|
82
|
4.80
|
156
|
156
|
82.90
|
|
|
|
|
80
|
4.90
|
149
|
149
|
80.80
|
|
|
|
|
73
|
5.00
|
143
|
143
|
78.70
|
|
|
|
|
71
|
5.10
|
137
|
137
|
76.40
|
|
|
|
|
67
|
5.20
|
131
|
131
|
74.00
|
|
|
|
|
65
|
5.30
|
126
|
126
|
72.00
|
|
|
|
|
63
|
5.40
|
121
|
121
|
69.00
|
|
|
|
|
60
|
5.50
|
116
|
116
|
67.60
|
|
|
|
|
58
|
5.60
|
111
|
111
|
65.70
|
|
|
|
|
56
|