ASTM Hardness Conversion Chart

Rockwell C Hardness Range

Approximate Hardness Conversion Numbers for Non-Austenitic Steels, According to ASTM E-140
The Conversion Values contained herein should be considered approximate only and may be inaccurate for specific applications

C A D 15N 30N 45N Vickers Knoop Brinell Tensile
150 kgt 60 kgt 100kgt 15kgt 30 kgt 45 kgt Hardness Hardness Hardness Strength
diamond diamond diamond diamond diamond diamond   500gr 3000kgt 1000 lbs/
              and over 10mm ball square in
68 85.6 76.9 93.2 84.4 75.4 940 920 .. ..
67 85.0 76.1 92.9 83.6 74.2 900 895 .. ..
66 84.5 75.4 92.5 82.8 73.3 865 870 .. ..
65 83.9 74.5 92.2 81.9 72.0 832 846 (739)  
64 83.4 73.8 91.8 81.1 71.0 800 822 (722)  
63 82.8 73.0 91.4 80.1 69.9 772 799 (705)  
62 82.3 72.2 91.1 79.3 68.8 745 776 (688)  
61 81.8 71.5 90.7 78.4 67.7 720 754 (670)  
60 81.2 70.7 90.2 77.5 66.6 697 732 (654)  
59 80.7 69.9 89.8 76.6 65.5 674 710 (634) 351
58 80.1 69.2 89.3 75.7 64.3 653 690 615 338
57 79.6 68.5 88.9 74.8 63.2 633 670 595 325
56 79.0 67.7 88.3 73.9 62.0 613 650 577 313
55 78.5 66.9 87.9 73.0 60.9 595 630 560 301
54 78.0 66.1 87.4 72.0 59.8 577 612 543 292
53 77.4 65.4 86.9 71.2 58.6 560 594 525 283
52 76.8 64.6 84.4 70.2 57.4 544 576 512 273
51 76.3 63.8 85.9 69.4 56.1 528 558 496 264
50 75.9 63.1 85.5 68.5 55.0 513 542 481 255
49 75.2 62.1 85.0 67.6 53.8 498 526 469 246
48 74.7 61.4 84.6 66.7 52.5 484 510 455 237
47 74.1 60.8 83.9 65.8 51.4 471 495 443 229
46 73.6 60 83.5 64.8 50.3 458 480 432 221
45 73.1 59.2 83.0 64.0 49.0 446 466 421 215
44 72.5 58.5 82.5 63.1 47.8 434 452 409 208
43 72.0 57.7 82.0 62.2 46.7 423 438 400 201
42 71.5 56.9 81.5 61.3 45.5 412 426 390 195
41 70.9 56.2 80.9 60.4 44.3 402 414 381 188
40 70.4 55.4 80.4 59.5 43.1 392 402 371 182
39 69.9 54.6 79.9 58.6 41.9 382 391 362 177
38 69.4 53.8 79.4 57.7 40.8 372 380 353 171
37 58.9 53.1 78.8 56.8 39.6 363 370 344 166
36 68.4 52.3 78.3 55.9 38.4 354 360 336 161
35 67.9 51.5 77.7 55.0 37.2 345 351 327 156
34 67.4 50.8 77.2 54.2 36.1 336 342 319 152
33 66.8 50.0 76.6 53.3 34.9 327 334 311 149
32 66.3 49.2 76.1 52.1 33.7 318 326 301 146
31 65.8 48.4 75.6 51.3 32.5 310 318 294 141
30 65.3 47.7 75.0 50.4 31.3 302 311 286 138
29 64.8 47.0 74.5 49.5 30.1 294 304 279 135
28 64.3 46.1 73.9 48.6 28.9 286 297 271 131
27 63.8 45.2 73.3 47.7 27.8 279 290 264 128
26 63.3 44.6 72.8 46.8 26.7 272 284 258 125
25 62.8 43.8 72.2 45.9 25.5 266 278 253 123
24 62.4 43.1 71.6 45.0 24.3 260 272 247 119
23 62.0 42.1 71.0 44.0 23.1 254 266 243 117
22 61.5 41.6 70.5 43.2 22.0 248 261 237 115
21 61.0 40.9 69.9 42.3 20.7 243 256 231 112
20 60.5 40.1 69.4 41.5 19.6 238 251 226 110
                   

 

Rockwell B Hardness Range

Approximate Hardness Conversion Numbers for Non-Austenitic Steels, according to ASTM E-140
The conversion values contained herein should be considered approximate only and may be inaccurate for Specific applications.

  Rockwell   Superficial Rockwell   Vickers Knoop Brinell Tensile Brinelll
B A E 15T 30T 45T Hardness Hardness Hardness Strength Hardness
100kgf 60 kgf 100 kgf 15 kgf 30 kgf 45 kg f   500gf 3000 kgf 1000 lbs/ 500 kgf
1/16"ball diamond 1/8" ball 1/16" ball 1/16"ball 1/16" ball   and over 10mm ball square in 10mm ball
100 61.5   93.1 83.1 72.9 240 261 240 116 201
99 60.9   82.8 82.5 71.9 234 246 234 114 195
98 602   92.5 81.8 709 228 241 228 109 189
97 59.5   92.1 81.1 699 222 236 222 105 184
96 58.9   91.8 80.4 689 216 231 216 102 179
95 58.3   91.5 79.8 67.9 210 226 210 100 175
94 57.6   91.2 79.1 669 205 221 205 98 171
93 57   90.8 784 659 200 216 200 94 167
92 56.4   90.5 77.8 64.8 195 211 195 92 163
91 55.8   90.2 77.1 63.8 190 206 190 90 160
90 55.2   89.9 76.4 62.8 186 201 186 89 157
89 54.6   89.5 76.8 61.8 180 196 180 88 164
88 64.0   89.2 75.1 60.8 176 192 176 86 151
87 53.4   88.9 74.4 59.8 172 188 172 84 148
86 52.8   88.6 73.8 58.8 169 184 169 83 145
85 52.3   88.2 73.1 57.8 165 180 165 82 142
84 51.7   87.9 72.4 56.8 162 176 162 81 140
83 51.1   87.6 71.8 55.8 159 173 159 80 137
82 50.6   87.3 71.1 54.8