HRC — hardened bulk parts
Fast routine checks on hardened steel with enough thickness and a suitable test surface.
Tools
Hardness Conversion HRC ↔ HV ↔ HB
Calculator + full steel hardness chart per ASTM E140 / ISO 18265 — enter one value, see every scale.
Supported range: 20.3 – 68 (Rockwell C (HRC))
Rockwell C (HRC)
45
Vickers (HV)
446
Brinell (HB)
421
Rockwell B (HRB)
—
Tensile (MPa)
1,455
Conversions are approximations per ASTM E140 / ISO 18265 for non-austenitic steel. Cross-scale conversion carries inherent tolerance; when a spec calls out a scale, measure in that scale directly.
Choose the measurement scale before converting
A converted value is for screening and communication. If a drawing names a scale, acceptance testing should use that scale directly.
HV — small, thin or case-hardened parts
Low-load and micro-Vickers measurements suit thin sections, small parts and hardness-depth traverses.
HB / HRB — softer material
Useful before hardening or for softer/coarser structures where HRC is outside its valid range.
Do not use a converted tensile-strength value as a substitute for an actual tensile test in design or product acceptance.
HRC vs HV vs HB — which scale, when
Steel hardness is measured on several scales. Rockwell C (HRC) is the workhorse for hardened parts — fast and easy to read. Vickers (HV) works at low loads, so it suits small or thin parts and carburized case layers (micro-Vickers). Brinell (HB) suits coarse structures, and Rockwell B (HRB) covers soft, unhardened steel.
This chart uses the published ASTM E140 and ISO 18265 correlations for non-austenitic steel. Values are approximate because each scale measures a different physical response (indent depth vs indent size); ±1–2 units of tolerance is normal for any cross-scale conversion.
At V.S. Heat Treatment we measure every lot in our in-house lab (Rockwell and micro-Vickers) and ship the readings with the parts. This is the same chart we use when a customer's spec arrives in HV or HB.
Full Conversion Chart
HV → HRC / HRB / HB / approximate tensile strength for steel. A dash marks ranges the standards do not correlate.
| Vickers (HV) | Rockwell C (HRC) | Rockwell B (HRB) | Brinell (HB) | Tensile (MPa) |
|---|---|---|---|---|
| 100 | — | 56.2 | 95 | 320 |
| 110 | — | 62.3 | 105 | 350 |
| 120 | — | 66.7 | 114 | 385 |
| 130 | — | 71.2 | 124 | 415 |
| 140 | — | 75 | 133 | 450 |
| 150 | — | 78.7 | 143 | 480 |
| 160 | — | 81.7 | 152 | 510 |
| 170 | — | 85 | 162 | 545 |
| 180 | — | 87.1 | 171 | 575 |
| 190 | — | 89.5 | 181 | 610 |
| 200 | — | 91.5 | 190 | 640 |
| 210 | — | 93.4 | 200 | 675 |
| 220 | — | 95 | 209 | 705 |
| 230 | — | 96.7 | 219 | 740 |
| 238 | 20.3 | 98 | 226 | 760 |
| 243 | 21 | 98.5 | 231 | 780 |
| 248 | 22 | 99 | 237 | 795 |
| 254 | 23 | 99.5 | 243 | 815 |
| 260 | 24 | 100 | 247 | 835 |
| 266 | 25 | — | 253 | 850 |
| 272 | 26 | — | 258 | 870 |
| 279 | 27 | — | 264 | 895 |
| 286 | 28 | — | 271 | 915 |
| 294 | 29 | — | 279 | 940 |
| 302 | 30 | — | 286 | 965 |
| 310 | 31 | — | 294 | 995 |
| 318 | 32 | — | 301 | 1,030 |
| 327 | 33 | — | 311 | 1,060 |
| 336 | 34 | — | 319 | 1,095 |
| 345 | 35 | — | 327 | 1,125 |
| 354 | 36 | — | 336 | 1,155 |
| 363 | 37 | — | 344 | 1,190 |
| 372 | 38 | — | 353 | 1,220 |
| 382 | 39 | — | 362 | 1,255 |
| 392 | 40 | — | 371 | 1,290 |
| 402 | 41 | — | 381 | 1,320 |
| 412 | 42 | — | 390 | 1,350 |
| 423 | 43 | — | 400 | 1,385 |
| 434 | 44 | — | 409 | 1,420 |
| 446 | 45 | — | 421 | 1,455 |
| 458 | 46 | — | 432 | 1,485 |
| 471 | 47 | — | 443 | 1,520 |
| 484 | 48 | — | 455 | 1,555 |
| 498 | 49 | — | 469 | 1,595 |
| 513 | 50 | — | 481 | 1,630 |
| 528 | 51 | — | 496 | 1,665 |
| 544 | 52 | — | 512 | 1,700 |
| 560 | 53 | — | 525 | 1,740 |
| 577 | 54 | — | 543 | 1,775 |
| 595 | 55 | — | 560 | 1,810 |
| 613 | 56 | — | 577 | 1,845 |
| 633 | 57 | — | 595 | 1,880 |
| 653 | 58 | — | 615 | — |
| 674 | 59 | — | 634 | — |
| 697 | 60 | — | 654 | — |
| 720 | 61 | — | 670 | — |
| 746 | 62 | — | 688 | — |
| 772 | 63 | — | 705 | — |
| 800 | 64 | — | 722 | — |
| 832 | 65 | — | 739 | — |
| 865 | 66 | — | — | — |
| 900 | 67 | — | — | — |
| 940 | 68 | — | — | — |
Conversions are approximations per ASTM E140 / ISO 18265 for non-austenitic steel. Cross-scale conversion carries inherent tolerance; when a spec calls out a scale, measure in that scale directly.
Hardness Conversion FAQ
What is the difference between HRC and HV?
HRC (Rockwell C) derives hardness from the depth of a conical diamond indent — fast, ideal for routine checks of hardened parts. HV (Vickers) derives it from the size of a pyramidal diamond indent and works at very low loads, so it measures small parts, thin sections and carburized case layers more precisely.
Why are converted values approximate?
Each scale measures a different physical response. The ASTM E140 / ISO 18265 tables are statistical correlations from test batches of steel, valid for non-austenitic grades with roughly ±1–2 units of tolerance. When you need an exact number, measure in the specified scale directly.
Which scale should small parts like screws and nuts be measured in?
Routine hardened parts: HRC. Very thin parts or carburized case layers: micro-Vickers (HV). Soft steel before hardening: HRB or HB. Our in-house lab runs both Rockwell and Vickers and reports readings with every lot.
Can I design against the tensile (MPa) column?
It is an ISO 18265 estimate — good for screening and rough spec checks only. Design against actual tensile test results, and note the standards stop correlating tensile above roughly 650 HV.
What we can tell you that the calculator cannot
Converting between scales is the easy half. Whether your part actually reaches the figure your drawing calls for depends on the steel, the section size and the condition it arrives in — and that is the part a table cannot answer. Send the drawing and we will tell you what is reachable, and say so plainly when it is not. We reply to quote requests within 24 hours.