Printed from Kezuriba (kezuriba.net/en/calc/hardness/)
Hardness conversion (steel)
Enter a value on any scale to get the others. Values between table rows are interpolated linearly. All conversions are approximate: the real relationship shifts with material, heat treatment and test conditions.
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Rockwell B (HRB) uses a 1/16 in ball. In the Shore sketch h ÷ h0 ≈ 0.39 (about HS 60 on the C-type instrument). Indents are enlarged for clarity.
▤Hardness conversion chart for steel
SAE J417 (1983 revision) / ASTM E140 Table 1 type “approximate equivalent hardness numbers for Rockwell C hardness of steel”, for non-austenitic carbon, alloy and tool steels. Values in ( ) below HRC 20 are outside the HRC range and for reference only.
| HRC | HV | HB | HS | HRB | HRA | Tensile MPa |
|---|---|---|---|---|---|---|
| 68 | 940 | — | 97 | — | 85.6 | — |
| 67 | 900 | — | 95 | — | 85 | — |
| 66 | 865 | — | 92 | — | 84.5 | — |
| 65 | 832 | 739 | 91 | — | 83.9 | — |
| 64 | 800 | 722 | 88 | — | 83.4 | — |
| 63 | 772 | 705 | 87 | — | 82.8 | — |
| 62 | 746 | 688 | 85 | — | 82.3 | — |
| 61 | 720 | 670 | 83 | — | 81.8 | — |
| 60 | 697 | 654 | 81 | — | 81.2 | — |
| 59 | 674 | 634 | 80 | — | 80.7 | — |
| 58 | 653 | 615 | 78 | — | 80.1 | — |
| 57 | 633 | 595 | 76 | — | 79.6 | — |
| 56 | 613 | 577 | 75 | — | 79 | — |
| 55 | 595 | 560 | 74 | — | 78.5 | 2075 |
| 54 | 577 | 543 | 72 | — | 78 | 2015 |
| 53 | 560 | 525 | 71 | — | 77.4 | 1950 |
| 52 | 544 | 512 | 69 | — | 76.8 | 1880 |
| 51 | 528 | 496 | 68 | — | 76.3 | 1820 |
| 50 | 513 | 481 | 67 | — | 75.9 | 1760 |
| 49 | 498 | 469 | 66 | — | 75.2 | 1695 |
| 48 | 484 | 455 | 64 | — | 74.7 | 1635 |
| 47 | 471 | 443 | 63 | — | 74.1 | 1580 |
| 46 | 458 | 432 | 62 | — | 73.6 | 1530 |
| 45 | 446 | 421 | 60 | — | 73.1 | 1480 |
| 44 | 434 | 409 | 58 | — | 72.5 | 1435 |
| 43 | 423 | 400 | 57 | — | 72 | 1385 |
| 42 | 412 | 390 | 56 | — | 71.5 | 1340 |
| 41 | 402 | 381 | 55 | — | 70.9 | 1295 |
| 40 | 392 | 371 | 54 | — | 70.4 | 1250 |
| 39 | 382 | 362 | 52 | — | 69.9 | 1215 |
| 38 | 372 | 353 | 51 | — | 69.4 | 1180 |
| 37 | 363 | 344 | 50 | — | 68.9 | 1160 |
| 36 | 354 | 336 | 49 | 109 | 68.4 | 1115 |
| 35 | 345 | 327 | 48 | 108.5 | 67.9 | 1080 |
| 34 | 336 | 319 | 47 | 108 | 67.4 | 1055 |
| 33 | 327 | 311 | 46 | 107.5 | 66.8 | 1025 |
| 32 | 318 | 301 | 44 | 107 | 66.3 | 1000 |
| 31 | 310 | 294 | 43 | 106 | 65.8 | 980 |
| 30 | 302 | 286 | 42 | 105.5 | 65.3 | 950 |
| 29 | 294 | 279 | 41 | 104.5 | 64.7 | 930 |
| 28 | 286 | 271 | 41 | 104 | 64.3 | 910 |
| 27 | 279 | 264 | 40 | 103 | 63.8 | 880 |
| 26 | 272 | 258 | 38 | 102.5 | 63.3 | 860 |
| 25 | 266 | 253 | 38 | 101.5 | 62.8 | 840 |
| 24 | 260 | 247 | 37 | 101 | 62.4 | 825 |
| 23 | 254 | 243 | 36 | 100 | 62 | 805 |
| 22 | 248 | 237 | 35 | 99 | 61.5 | 785 |
| 21 | 243 | 231 | 35 | 98.5 | 61 | 770 |
| 20 | 238 | 226 | 34 | 97.8 | 60.5 | 760 |
| (18) | 230 | 219 | 33 | 96.7 | — | 730 |
| (16) | 222 | 212 | 32 | 95.5 | — | 705 |
| (14) | 213 | 203 | 31 | 93.9 | — | 675 |
| (12) | 204 | 194 | 29 | 92.3 | — | 650 |
| (10) | 196 | 187 | 28 | 90.7 | — | 620 |
| (8) | 188 | 179 | 27 | 89.5 | — | 600 |
| (6) | 180 | 171 | 26 | 87.1 | — | 580 |
| (4) | 173 | 165 | 25 | 85.5 | — | 550 |
| (2) | 166 | 158 | 24 | 83.5 | — | 530 |
| (0) | 160 | 152 | 24 | 81.7 | — | 515 |
Notes
- This chart is for carbon, alloy and tool steels (non-austenitic). Austenitic stainless, high-manganese steel and cold-worked material can fall outside it.
- Do not use it for aluminum or copper alloys; non-ferrous metals have their own conversion tables.
- Shore (HS) values differ slightly in charts that follow JIS B 7731.
- Tensile strength (MPa ≈ N/mm²) is a rough guide only. 1 MPa ≈ 145 psi; use the unit converter for ksi.
📚Sources
We compared the charts below and use values that agree in at least two of them (most Japanese charts reproduce the same SAE J417 table).
- NBK (Nabeya Bi-tech) nbk1560.com
- Miki Pulley mikipulley.co.jp
- MISUMI jp.misumi-ec.com
- OSG osg.co.jp
- Kyocera (cutting tools) asia.kyocera.com
- Mitutoyo (Japan) mitutoyo.co.jp
- Mitutoyo America mitutoyo.com
- Buehler (ITW) / Wilson buehler.com