Hardness Comparison Table
Brinell 3000kg load 10mm Ball Ø of Impression mm | Hardness No. HB | Diamond Pyramid No. (Vickers) HV | Rockwell C. Scale 150kg Diamond Cone | Rockwell B. Scaled 100kg 1/16 " Ball | Equivalent Tensile Strength for Steel | |
---|---|---|---|---|---|---|
N/mm² | Tons/Sq. In. | |||||
2.05 | 899 | - | - | - | 3027 | 196 |
2.10 | 856 | - | - | - | 2888 | 187 |
2.15 | 817 | - | - | - | 2749 | 178 |
2.20 | 780 | 1150 | 70 | - | 2641 | 171 |
2.25 | 745 | 1050 | 68 | - | 2517 | 163 |
2.30 | 712 | 960 | 66 | - | 2409 | 156 |
2.35 | 682 | 885 | 64 | - | 2286 | 148 |
2.40 | 653 | 820 | 62 | - | 2193 | 142 |
2.45 | 627 | 765 | 60 | - | 2116 | 137 |
2.50 | 601 | 717 | 58 | - | 2023 | 131 |
2.55 | 578 | 675 | 57 | - | 1946 | 126 |
2.60 | 555 | 633 | 55 | 120 | 1869 | 121 |
2.65 | 534 | 598 | 53 | 119 | 1792 | 116 |
2.70 | 514 | 567 | 52 | 119 | 1730 | 112 |
2.75 | 495 | 540 | 50 | 117 | 1668 | 108 |
2.80 | 477 | 515 | 49 | 117 | 1606 | 104 |
2.85 | 461 | 494 | 47 | 116 | 1544 | 100 |
2.90 | 444 | 472 | 46 | 115 | 1498 | 97 |
2.95 | 429 | 454 | 45 | 115 | 1452 | 94 |
3.00 | 415 | 437 | 44 | 114 | 1405 | 91 |
3.05 | 401 | 420 | 42 | 113 | 1359 | 88 |
3.10 | 388 | 404 | 41 | 112 | 1297 | 84 |
3.15 | 375 | 389 | 40 | 112 | 1266 | 82 |
3.20 | 363 | 375 | 38 | 110 | 1220 | 79 |
3.25 | 352 | 363 | 37 | 110 | 1174 | 76 |
3.30 | 341 | 350 | 36 | 109 | 1143 | 74 |
3.35 | 331 | 339 | 35 | 109 | 1112 | 72 |
3.40 | 321 | 327 | 34 | 108 | 1081 | 70 |
3.45 | 311 | 316 | 33 | 108 | 1050 | 68 |
3.50 | 302 | 305 | 32 | 107 | 1019 | 66 |
3.55 | 293 | 296 | 31 | 106 | 988 | 64 |
3.60 | 285 | 287 | 30 | 105 | 958 | 62 |
3.65 | 277 | 279 | 29 | 104 | 927 | 60 |
3.70 | 269 | 270 | 28 | 104 | 911 | 59 |
3.75 | 262 | 263 | 26 | 103 | 880 | 57 |
3.80 | 255 | 256 | 25 | 102 | 849 | 55 |
3.85 | 248 | 248 | 24 | 102 | 834 | 54 |
3.90 | 241 | 241 | 23 | 100 | 803 | 52 |
3.95 | 235 | 235 | 22 | 99 | 788 | 51 |
4.00 | 229 | 229 | 21 | 98 | 772 | 50 |
4.05 | 223 | 223 | 20 | 97 | 757 | 49 |
4.10 | 217 | 217 | 18 | 96 | 726 | 47 |
4.15 | 212 | 212 | 17 | 96 | 710 | 46 |
4.20 | 207 | 207 | 16 | 95 | 695 | 45 |
4.25 | 201 | 202 | 15 | 94 | 680 | 44 |
4.30 | 197 | 197 | 13 | 93 | 664 | 43 |
4.35 | 192 | 192 | 12 | 92 | 649 | 42 |
4.40 | 187 | 187 | 10 | 91 | 633 | 41 |
4.45 | 183 | 183 | 9 | 90 | 618 | 40 |
4.50 | 179 | 179 | 8 | 89 | 610 | 39.5 |
4.55 | 174 | 174 | 7 | 88 | 602 | 39 |
4.60 | 170 | 170 | 6 | 87 | 595 | 38.5 |
4.65 | 167 | 166 | 4 | 86 | 587 | 38 |
4.70 | 163 | 163 | 3 | 85 | 579 | 37.5 |
4.75 | 159 | 159 | 2 | 84 | 564 | 36.5 |
4.80 | 156 | 156 | 1 | 83 | 556 | 36 |
4.85 | 152 | 153 | 0 | 82 | 541 | 35 |
4.90 | 149 | 149 | -1 | 81 | 525 | 34 |
4.95 | 146 | 146 | -2 | 80 | 517 | 33.5 |
5.00 | 143 | 143 | -3 | 79 | 510 | 33 |
5.05 | 140 | 140 | -4 | 78 | 494 | 32 |
5.10 | 137 | 137 | -6 | 77 | 486 | 31.5 |
5.15 | 134 | 134 | -7 | 76 | 479 | 31 |
5.20 | 131 | 131 | -9 | 74 | 463 | 30 |
5.25 | 128 | 128 | -11 | 73 | 456 | 29.5 |
5.30 | 126 | 126 | -12 | 72 | 448 | 29 |
5.35 | 123 | 124 | -14 | 71 | 440 | 28.5 |
5.40 | 121 | 121 | -16 | 70 | 432 | 28 |
5.45 | 118 | 118 | -17 | 69 | 417 | 27 |
5.50 | 116 | 116 | -19 | 68 | 409 | 26.5 |
5.55 | 114 | 114 | -20 | 67 | 402 | 26 |
5.60 | 111 | 112 | - | 66 | 394 | 25.5 |
5.65 | 109 | 109 | - | 65 | 386 | 25 |
5.70 | 107 | 107 | - | 64 | 378 | 24.5 |
5.75 | 105 | 105 | - | 62 | 371 | 24 |
5.80 | 103 | 103 | - | 61 | 363 | 23.5 |
5.85 | 101 | 101 | - | 60 | 355 | 23 |
5.90 | 99.2 | 99 | - | 59 | 351 | 22.75 |
5.95 | 97.3 | 97 | - | 57 | 347 | 22.5 |
6.00 | 95.5 | 95 | - | 56 | 340 | 22 |
The equivalents given are approximations and must not be accepted as rigid. Certain conditions, especially the incidence of cold work, can alter the relation between hardness and tensile strength profoundly.
The hardness systems, given above, are in general use in industry, and it is convenient to be able to translate the results of one in terms of the hardness units of the other.
The table is offered as a guide only, and should be used with due discretion.