According to the German standard DIN50150, the following is a comparison table of the commonly used ranges of steel tensile strength and Vickers hardness, Brinell hardness, and Rockwell hardness.
Rm N/mm2
|
Vickers hardness HV
|
Brinell hardness HB
|
Rockwell hardness HRC
|
Rockwell hardness HRB
|
250
|
80
|
76
|
-
|
|
270
|
85
|
80.7
|
-
|
|
285
|
90
|
85.2
|
-
|
|
305
|
95
|
90.2
|
-
|
|
320
|
100
|
95
|
-
|
|
335
|
105
|
99.8
|
-
|
|
350
|
110
|
105
|
-
|
|
370
|
115
|
109
|
-
|
|
380
|
120
|
114
|
-
|
|
400
|
125
|
119
|
-
|
64.5
|
415
|
130
|
124
|
-
|
67.5
|
430
|
135
|
128
|
-
|
70
|
450
|
140
|
133
|
-
|
73
|
465
|
145
|
138
|
-
|
75
|
480
|
150
|
143
|
-
|
77
|
490
|
155
|
147
|
-
|
78
|
510
|
160
|
152
|
-
|
80
|
530
|
165
|
156
|
-
|
82.1
|
545
|
170
|
162
|
-
|
84
|
560
|
175
|
166
|
-
|
84.9
|
575
|
180
|
171
|
-
|
86
|
595
|
185
|
176
|
-
|
87.5
|
610
|
190
|
181
|
-
|
88.6
|
625
|
195
|
185
|
-
|
89.6
|
640
|
200
|
190
|
-
|
90.9
|
660
|
205
|
195
|
-
|
92
|
675
|
210
|
199
|
-
|
93
|
690
|
215
|
204
|
-
|
94
|
705
|
220
|
209
|
-
|
95
|
720
|
225
|
214
|
-
|
95.6
|
740
|
230
|
219
|
-
|
97
|
755
|
235
|
223
|
-
|
97.5
|
770
|
240
|
228
|
20.3
|
98.4
|
785
|
245
|
233
|
21.3
|
99
|
800
|
250
|
238
|
22.2
|
100
|
820
|
255
|
242
|
23.1
|
101
|
835
|
260
|
247
|
24
|
|
850
|
265
|
252
|
24.8
|
|
865
|
270
|
257
|
25.6
|
|
880
|
275
|
261
|
26.4
|
103
|
900
|
280
|
266
|
27.1
|
|
915
|
285
|
271
|
27.8
|
|
930
|
290
|
276
|
28.5
|
|
950
|
295
|
280
|
29.2
|
105.5
|
965
|
300
|
285
|
29.8
|
|
995
|
310
|
295
|
31
|
|
1030
|
320
|
304
|
32.2
|
|
1060
|
330
|
314
|
33.3
|
|
1095
|
340
|
323
|
34.4
|
|
1125
|
350
|
333
|
35.5
|
|
1115
|
360
|
342
|
36.6
|
|
1190
|
370
|
352
|
37.7
|
|
1220
|
380
|
361
|
38.8
|
|
1255
|
390
|
371
|
39.8
|
|
1290
|
400
|
380
|
40.8
|
|
1320
|
410
|
390
|
41.8
|
|
1350
|
420
|
399
|
42.7
|
|
1385
|
430
|
409
|
43.6
|
|
1420
|
440
|
418
|
44.5
|
|
1455
|
450
|
428
|
45.3
|
|
1485
|
460
|
437
|
46.1
|
|
1520
|
470
|
447
|
46.9
|
|
1555
|
480
|
-456
|
47.7
|
|
1595
|
490
|
-466
|
48.4
|
|
1630
|
500
|
-475
|
49.1
|
|
1665
|
510
|
-485
|
49.8
|
|
1700
|
520
|
-494
|
50.5
|
|
1740
|
530
|
-504
|
51.1
|
|
1775
|
540
|
-513
|
51.7
|
|
1810
|
550
|
-523
|
52.3
|
|
1845
|
560
|
-532
|
53
|
|
1880
|
570
|
-542
|
53.6
|
|
1920
|
580
|
-551
|
54.1
|
|
1955
|
590
|
-561
|
54.7
|
|
1995
|
600
|
-570
|
55.2
|
|
2030
|
610
|
-580
|
55.7
|
|
2070
|
620
|
-589
|
56.3
|
|
2105
|
630
|
-599
|
56.8
|
|
2145
|
640
|
-608
|
57.3
|
|
2180
|
650
|
-618
|
57.8
|
|
|
660
|
|
58.3
|
|
|
670
|
|
58.8
|
|
|
680
|
|
59.2
|
|
|
690
|
|
59.7
|
|
|
700
|
|
60.1
|
|
|
720
|
|
61
|
|
|
740
|
|
61.8
|
|
|
760
|
|
62.5
|
|
|
780
|
|
63.3
|
|
|
800
|
|
64
|
|
|
820
|
|
64.7
|
|
|
840
|
|
65.3
|
|
|
860
|
|
65.9
|
|
|
880
|
|
66.4
|
|
|
900
|
|
67
|
|
|
920
|
|
67.5
|
|
|
940
|
|
68
|
|
Hardness test is a simple and easy test method in mechanical performance test. In order to replace certain mechanical performance tests with hardness tests, a more accurate conversion relationship between hardness and strength is required in production.
Practice has proved that between various hardness values of metal materials, there is an approximate corresponding relationship between the hardness value and the strength value. Because the hardness value is determined by the initial plastic deformation resistance and the continued plastic deformation resistance, the higher the strength of the material, the higher the plastic deformation resistance and the higher the hardness value.
|