Hardness Conversion Chart
Complete ASTM E140 hardness conversion table for non-austenitic steels. Convert between Rockwell C (HRC), Rockwell A (HRA), Rockwell B (HRB), Vickers (HV), and Brinell (HB).
Rockwell C Scale (HRC 20–68)
| HRC | HRA | HRB | Vickers (HV) | Brinell (HB) | Tensile (ksi) |
|---|---|---|---|---|---|
| 68 | 85.6 | — | 940 | — | — |
| 67 | 85.0 | — | 900 | — | — |
| 66 | 84.5 | — | 865 | — | — |
| 65 | 83.9 | — | 832 | 739 | — |
| 64 | 83.4 | — | 800 | 722 | — |
| 63 | 82.8 | — | 772 | 706 | — |
| 62 | 82.3 | — | 746 | 688 | — |
| 61 | 81.8 | — | 720 | 670 | — |
| 60 | 81.2 | — | 697 | 654 | — |
| 59 | 80.7 | — | 674 | 634 | 351 |
| 58 | 80.1 | — | 653 | 615 | 338 |
| 57 | 79.6 | — | 633 | 595 | 325 |
| 56 | 79.0 | — | 613 | 577 | 313 |
| 55 | 78.5 | — | 595 | 560 | 301 |
| 54 | 78.0 | — | 577 | 543 | 292 |
| 53 | 77.4 | — | 560 | 525 | 283 |
| 52 | 76.8 | — | 544 | 512 | 274 |
| 51 | 76.3 | — | 528 | 496 | 266 |
| 50 | 75.9 | — | 513 | 481 | 259 |
| 49 | 75.2 | — | 498 | 469 | 251 |
| 48 | 74.7 | — | 484 | 455 | 243 |
| 47 | 74.1 | — | 471 | 443 | 237 |
| 46 | 73.6 | — | 458 | 432 | 231 |
| 45 | 73.1 | — | 446 | 421 | 226 |
| 44 | 72.5 | — | 434 | 409 | 220 |
| 43 | 72.0 | — | 423 | 400 | 215 |
| 42 | 71.5 | — | 412 | 390 | 210 |
| 41 | 70.9 | — | 402 | 381 | 205 |
| 40 | 70.4 | — | 392 | 371 | 200 |
| 39 | 69.9 | — | 382 | 362 | 196 |
| 38 | 69.4 | — | 372 | 353 | 191 |
| 37 | 68.9 | — | 363 | 344 | 187 |
| 36 | 68.4 | 109.0 | 354 | 336 | 183 |
| 35 | 67.9 | 108.5 | 345 | 327 | 179 |
| 34 | 67.4 | 108.0 | 336 | 319 | 175 |
| 33 | 66.8 | 107.5 | 327 | 311 | 171 |
| 32 | 66.3 | 107.0 | 318 | 301 | 167 |
| 31 | 65.8 | 106.0 | 310 | 294 | 163 |
| 30 | 65.2 | 105.5 | 302 | 286 | 160 |
| 29 | 64.7 | 104.5 | 294 | 279 | 156 |
| 28 | 64.3 | 104.0 | 286 | 271 | 153 |
| 27 | 63.8 | 103.5 | 279 | 264 | 150 |
| 26 | 63.3 | 103.0 | 272 | 258 | 147 |
| 25 | 62.8 | 102.0 | 266 | 253 | 144 |
| 24 | 62.4 | 101.5 | 260 | 247 | 141 |
| 23 | 62.0 | 101.0 | 254 | 243 | 139 |
| 22 | 61.5 | 100.0 | 248 | 237 | 137 |
| 21 | 61.0 | 99.5 | 243 | 231 | 135 |
| 20 | 60.5 | 99.0 | 238 | 226 | 133 |
Rockwell B Scale (HRB 60–100)
For softer steels below HRC 20:
| HRB | Vickers (HV) | Brinell (HB) | Approx. Tensile |
|---|---|---|---|
| 100 | 240 | 226 | 133 ksi |
| 99 | 234 | 222 | 131 ksi |
| 98 | 228 | 218 | 128 ksi |
| 97 | 222 | 212 | 125 ksi |
| 96 | 216 | 207 | 122 ksi |
| 95 | 210 | 202 | 119 ksi |
| 94 | 205 | 197 | 117 ksi |
| 93 | 200 | 192 | 114 ksi |
| 92 | 195 | 187 | 112 ksi |
| 91 | 190 | 183 | 109 ksi |
| 90 | 185 | 179 | 107 ksi |
| 89 | 180 | 174 | 105 ksi |
| 88 | 176 | 170 | 103 ksi |
| 87 | 172 | 167 | 101 ksi |
| 86 | 169 | 163 | 99 ksi |
| 85 | 165 | 159 | 97 ksi |
| 84 | 162 | 156 | 95 ksi |
| 83 | 159 | 153 | 93 ksi |
| 82 | 155 | 149 | 91 ksi |
| 81 | 152 | 146 | 89 ksi |
| 80 | 149 | 143 | 88 ksi |
| 79 | 146 | 140 | 86 ksi |
| 78 | 143 | 137 | 84 ksi |
| 77 | 140 | 134 | 83 ksi |
| 76 | 137 | 131 | 81 ksi |
| 75 | 135 | 128 | 79 ksi |
| 70 | 120 | 114 | 72 ksi |
| 65 | 105 | 100 | 64 ksi |
| 60 | 95 | 90 | 58 ksi |
Quick Conversion Formulas (Approximate)
- HV ≈ HB × 1.05 (rough estimate for HB 200–450)
- Tensile (ksi) ≈ HB × 0.5 (rough estimate for carbon/alloy steels)
- Tensile (MPa) ≈ HB × 3.45 (rough estimate)
- HRC ≈ (HB/10) – 3 (very rough, for HB 250-450 range only)
These formulas are for quick mental estimates only. Use the table above for accurate conversions.
⚠️ Limitations
- Per ASTM E140 — valid for non-austenitic steels only.
- Austenitic stainless steels, nickel alloys, and non-ferrous metals have separate conversion tables.
- Conversions become less reliable at extreme hardness values (HRC > 60).
- Surface hardness may differ from core hardness on case-hardened parts.
Interactive Hardness Conversion
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