Hardness conversion
HV ↔ HRC ↔ HRB ↔ HB ↔ tensile estimate
ASTM E140 / ISO 18265 conversion across the four common hardness scales plus an estimated tensile strength for steels (Sut ≈ 3.4·HV in MPa for low-alloy, less reliable for stainless / Ni-base).
Convert from
scale
value
equivalents
Vickers HV204
Rockwell C (HRC)—
Rockwell B (HRB)96
Brinell HB195
Tensile (est.)— MPa
Sources: ASTM E140 Table 1 · ISO 18265 · NACE MR0175 hardness gates. Tensile estimate is the Tabor relation (Sut ≈ 3.0–3.4·HV) — acceptable for low-alloy steels, less reliable for stainless / Ni-base.
NACE MR0175 / ISO 15156 sour-service gates
| item | max HRC | max HV | your value | verdict |
|---|---|---|---|---|
| Carbon steel parent (sour) | 22 | 248 | HV 204 / HRC — | PASS |
| Carbon steel weld + HAZ (sour) | 22 | 250 | HV 204 / HRC — | PASS |
| 4140 / 4145 Q&T (sour) | 22 | 248 | HV 204 / HRC — | PASS |
| Inconel 625 / 825 (sour) | 35 | 345 | HV 204 / HRC — | PASS |
| Duplex 22Cr (sour) | 28 | 286 | HV 204 / HRC — | PASS |
| Super duplex 25Cr (sour) | 32 | 318 | HV 204 / HRC — | PASS |
| 13Cr martensitic SS (sour, low pH) | 23 | 254 | HV 204 / HRC — | PASS |
Full conversion table (steels)
| HV | HRC | HRB | HB | tensile MPa |
|---|---|---|---|---|
| 940 | 68 | — | — | — |
| 900 | 67 | — | — | — |
| 865 | 66 | — | — | — |
| 832 | 65 | — | — | — |
| 800 | 64 | — | — | 2400 |
| 772 | 63 | — | — | — |
| 746 | 62 | — | — | — |
| 720 | 61 | — | — | — |
| 697 | 60 | — | — | 2200 |
| 674 | 59 | — | — | — |
| 653 | 58 | — | — | — |
| 633 | 57 | — | — | — |
| 613 | 56 | — | — | — |
| 595 | 55 | — | — | 1900 |
| 577 | 54 | — | — | — |
| 560 | 53 | — | — | — |
| 544 | 52 | — | — | — |
| 528 | 51 | — | — | — |
| 513 | 50 | — | 481 | 1670 |
| 498 | 49 | — | — | — |
| 484 | 48 | — | — | — |
| 471 | 47 | — | 442 | — |
| 458 | 46 | — | — | — |
| 446 | 45 | — | 421 | 1480 |
| 434 | 44 | — | — | — |
| 423 | 43 | — | 400 | — |
| 412 | 42 | — | — | — |
| 402 | 41 | — | — | — |
| 392 | 40 | — | 371 | 1290 |
| 382 | 39 | — | — | — |
| 372 | 38 | — | 353 | — |
| 363 | 37 | — | — | — |
| 354 | 36 | — | 336 | 1170 |
| 345 | 35 | — | — | — |
| 336 | 34 | — | 319 | — |
| 327 | 33 | — | — | — |
| 318 | 32 | — | 301 | 1080 |
| 310 | 31 | — | — | — |
| 302 | 30 | — | 285 | 1020 |
| 294 | 29 | — | — | — |
| 286 | 28 | — | 271 | — |
| 279 | 27 | — | — | — |
| 272 | 26 | — | 258 | 920 |
| 266 | 25 | — | — | — |
| 260 | 24 | — | 247 | — |
| 254 | 23 | — | — | — |
| 248 | 22 | — | 235 | 830 |
| 243 | 21 | — | — | — |
| 238 | 20 | 100 | 226 | — |
| 230 | — | 99 | 219 | — |
| 222 | — | 98 | 212 | 750 |
| 213 | — | 97 | 203 | — |
| 204 | — | 96 | 195 | — |
| 196 | — | 95 | 187 | 660 |
| 188 | — | 94 | 179 | — |
| 180 | — | 93 | 171 | — |
| 173 | — | 92 | 165 | — |
| 166 | — | 91 | 158 | — |
| 160 | — | 90 | 152 | 540 |
| 153 | — | 89 | 145 | — |
| 147 | — | 88 | 140 | — |
| 142 | — | 87 | 135 | — |
| 137 | — | 86 | 130 | — |
| 132 | — | 85 | 125 | 460 |
| 127 | — | 84 | 121 | — |
| 122 | — | 83 | 116 | — |
| 117 | — | 82 | 112 | — |
| 113 | — | 81 | 108 | — |
| 109 | — | 80 | 104 | 380 |