Steel hardness conversion
HRC ↔ HB ↔ HV ↔ HRA ↔ HRB converter per ASTM E140 and ISO 18265
Full conversion table
| HRC | HB | HV | HRA | HRB | σв, МПа |
|---|---|---|---|---|---|
| 68 | — | 940 | 85.6 | — | — |
| 67 | — | 900 | 85 | — | — |
| 66 | — | 865 | 84.5 | — | — |
| 65 | 739 | 832 | 84 | — | — |
| 64 | 722 | 800 | 83.4 | — | — |
| 63 | 706 | 772 | 82.8 | — | — |
| 62 | 688 | 746 | 82.3 | — | — |
| 61 | 670 | 720 | 81.8 | — | — |
| 60 | 654 | 697 | 81.2 | — | 2255 |
| 59 | 634 | 674 | 80.7 | — | 2185 |
| 58 | 615 | 653 | 80.1 | — | 2120 |
| 57 | 595 | 633 | 79.6 | — | 2050 |
| 56 | 577 | 613 | 79 | — | 1990 |
| 55 | 560 | 595 | 78.5 | — | 1930 |
| 54 | 543 | 577 | 78 | — | 1875 |
| 53 | 525 | 560 | 77.4 | — | 1810 |
| 52 | 512 | 544 | 76.8 | — | 1765 |
| 51 | 496 | 528 | 76.3 | — | 1710 |
| 50 | 481 | 513 | 75.9 | — | 1660 |
| 49 | 469 | 498 | 75.2 | — | 1620 |
| 48 | 455 | 484 | 74.7 | — | 1570 |
| 47 | 443 | 471 | 74.1 | — | 1530 |
| 46 | 432 | 458 | 73.6 | — | 1490 |
| 45 | 421 | 446 | 73.1 | — | 1450 |
| 44 | 409 | 434 | 72.5 | — | 1410 |
| 43 | 400 | 423 | 72 | — | 1380 |
| 42 | 390 | 412 | 71.5 | — | 1345 |
| 41 | 381 | 402 | 70.9 | — | 1315 |
| 40 | 371 | 392 | 70.4 | — | 1280 |
| 39 | 362 | 382 | 69.9 | — | 1250 |
| 38 | 353 | 372 | 69.4 | — | 1220 |
| 37 | 344 | 363 | 68.9 | — | 1195 |
| 36 | 336 | 354 | 68.4 | 109 | 1160 |
| 35 | 327 | 345 | 67.9 | 109 | 1130 |
| 34 | 319 | 336 | 67.4 | 108 | 1105 |
| 33 | 311 | 327 | 66.8 | 108 | 1080 |
| 32 | 301 | 318 | 66.3 | 107 | 1055 |
| 31 | 294 | 310 | 65.8 | 106 | 1030 |
| 30 | 286 | 302 | 65.3 | 105 | 1005 |
| 29 | 279 | 294 | 64.7 | 104 | 980 |
| 28 | 271 | 286 | 64.3 | 103 | 950 |
| 27 | 264 | 279 | 63.8 | 102 | 930 |
| 26 | 258 | 272 | 63.3 | 102 | 910 |
| 25 | 253 | 266 | 62.8 | 101 | 880 |
| 24 | 247 | 260 | 62.4 | 100 | 860 |
| 23 | 243 | 254 | 62 | 99 | 840 |
| 22 | 237 | 248 | 61.5 | 98 | 820 |
| 21 | 231 | 243 | 61 | 97 | 800 |
| 20 | 226 | 238 | 60.5 | 96 | 780 |
| — | 219 | 230 | — | 95 | 755 |
| — | 212 | 222 | — | 94 | 730 |
| — | 203 | 213 | — | 93 | 695 |
| — | 194 | 203 | — | 91 | 670 |
| — | 187 | 195 | — | 90 | 645 |
| — | 179 | 187 | — | 88 | 615 |
| — | 170 | 178 | — | 87 | 585 |
| — | 162 | 169 | — | 85 | 560 |
| — | 156 | 162 | — | 84 | 540 |
| — | 149 | 155 | — | 82 | 515 |
| — | 143 | 148 | — | 80 | 490 |
| — | 137 | 142 | — | 78 | 470 |
| — | 131 | 135 | — | 76 | 450 |
| — | 126 | 130 | — | 74 | 430 |
| — | 121 | 125 | — | 72 | 415 |
| — | 116 | 120 | — | 70 | 400 |
| — | 111 | 115 | — | 67 | 385 |
| — | 105 | 109 | — | 64 | 365 |
| — | 100 | 104 | — | 60 | 345 |
Calculators — FAQ
Which materials does this work for?+
ASTM E140 / ISO 18265 conversions are valid for carbon and low-alloy steels in normalized or hardened state. For austenitic stainless, non-ferrous metals, aluminum — different coefficients apply, this table cannot be used.
How accurate is the conversion?+
Within ±2 HRC or ±15 HB for typical structural steels. For critical applications (incoming inspection, HT verification on critical parts) measure directly in the required scale — this table is for orientation.
Where does the tensile estimate come from?+
Empirical rule: σ_uts ≈ HB × 3.45 for steels with HB 100-400. Accuracy ±10%. Above HB 400 the relationship becomes less linear — use materials tables or actual tensile testing.
What hardness levels do you achieve?+
We don't run heat treatment ourselves but accept any starting state of forging/stock. If your finished part needs hardening, we route it to HT partners (Ust-Kamenogorsk or Almaty) and return it ready.
All calculators
Need parts machined?
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