Hardness Comparison Table
BRINELL 3000 Kg. LOAD 10mm BALL | DIAMOND PYRAMID NUMBER (VICKERS) HV | ROCKWELL NUMBER | EQUIVALENT TENSILE STRENGTH FOR STEEL | ||||
---|---|---|---|---|---|---|---|
Dia of Impression (mm) | Hardness Number HB | C. Scale 150 kg Diamond Cone | B. Scale 100 kg 1/16 inch Ball | 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.