Hardness Conversion Calculator
Convert steel hardness between Rockwell C (HRC), Rockwell B (HRB), Vickers (HV), Brinell (HB) and approximate tensile strength. Enter a value on any scale and the equivalents are looked up from the standard conversion tables for steel.
Hardness converter
Conversions follow ASTM E140 / SAE J417 approximations for carbon and low-alloy steel. They are estimates — not valid for all alloys, and never a substitute for an actual test.
HRC to HB, HV and tensile strength chart
| HRC | Vickers HV | Brinell HB | Tensile (MPa) | Tensile (ksi) |
|---|---|---|---|---|
| 68 | 940 | — | — | — |
| 67 | 900 | — | — | — |
| 66 | 865 | — | — | — |
| 65 | 832 | 739 | — | — |
| 64 | 800 | 722 | — | — |
| 63 | 772 | 706 | — | — |
| 62 | 746 | 688 | — | — |
| 61 | 720 | 670 | — | — |
| 60 | 697 | 654 | 2180 | 316 |
| 58 | 653 | 615 | 1990 | 289 |
| 56 | 613 | 577 | 1840 | 267 |
| 54 | 577 | 543 | 1710 | 248 |
| 52 | 544 | 512 | 1590 | 231 |
| 50 | 513 | 481 | 1500 | 218 |
| 48 | 484 | 455 | 1400 | 203 |
| 46 | 458 | 432 | 1320 | 191 |
| 44 | 434 | 409 | 1240 | 180 |
| 42 | 412 | 390 | 1180 | 171 |
| 40 | 392 | 371 | 1110 | 161 |
| 38 | 372 | 353 | 1060 | 154 |
| 36 | 354 | 336 | 1010 | 146 |
| 34 | 336 | 319 | 950 | 138 |
| 32 | 318 | 301 | 900 | 131 |
| 30 | 302 | 286 | 860 | 125 |
| 28 | 286 | 271 | 820 | 119 |
| 26 | 272 | 258 | 780 | 113 |
| 24 | 260 | 247 | 750 | 109 |
| 22 | 248 | 235 | 720 | 104 |
| 20 | 238 | 226 | 690 | 100 |
Which hardness scale should you use?
- HRC (Rockwell C) — hardened steel, tool steel, knife blades. Diamond cone, 150 kgf. Practical range roughly 20–68 HRC.
- HRB (Rockwell B) — mild steel, annealed material, brass and aluminum. 1/16 in ball, 100 kgf.
- HB (Brinell) — castings, forgings and coarse-grained material; the large ball averages over a bigger area.
- HV (Vickers) — thin sections, coatings, case-hardened layers and micro-hardness work; one continuous scale across all hardness levels.
A useful rule of thumb for steel: tensile strength (MPa) ≈ 3.45 × HB.
Frequently asked questions
How do I convert HRC to Brinell?
Use a conversion table: for steel, 40 HRC is about 371 HB, 50 HRC about 481 HB, and 60 HRC about 654 HB. Conversions are approximate because the two tests measure different indentation behaviour.
How do I convert hardness to tensile strength?
For carbon and low-alloy steel a common approximation is tensile strength (MPa) is about 3.45 x Brinell hardness (HB). A 200 HB steel is roughly 690 MPa. This is an estimate only, not a substitute for a tensile test.
What is the difference between HRC and HRB?
Both are Rockwell scales with different indenters and loads. HRC uses a diamond cone at 150 kgf for hardened steel; HRB uses a 1/16 in ball at 100 kgf for softer steels, brass and aluminum. Use HRB below about 20 HRC.
Are hardness conversions exact?
No. ASTM E140 states conversions are approximate and material-dependent. They are reliable for carbon and low-alloy steels but should not be applied blindly to stainless, non-ferrous alloys, or cold-worked material.
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