Hardness Conversion.
Convert between Rockwell C (HRC), Rockwell B (HRB), Vickers (HV), Brinell (HB), Knoop (HK), and tensile strength. Based on ASTM E140 standard conversion table for steels.
Pick input scale
Rockwell C
HRC
Rockwell B
HRB
Vickers
HV
Brinell
HB (3000 kgf)
Knoop
HK
Tensile
UTS (MPa)
Equivalent values
HRC
—
Rockwell C
HRB
—
Rockwell B
HV
—
Vickers
HB
—
Brinell 3000 kgf
HK
—
Knoop 500 gf
UTS
—
MPa (≈3.45·HB)
Note on accuracy. Hardness conversion is approximate. Values are based on ASTM E140 for non-austenitic steels. For non-ferrous materials (aluminium, copper, brass), conversions are less reliable — measure on the correct scale where possible. Reading errors of ±2 HRC and ±20 HV are normal between scales.
Common reference points
| Material / Condition | HRC | HV | HB | UTS (MPa) |
|---|---|---|---|---|
| Mild steel — annealed | — | 120 | 114 | 390 |
| EN8 — normalised | 20 | 240 | 228 | 790 |
| EN24 — Q&T | 32 | 319 | 304 | 1050 |
| Spring steel — tempered | 45 | 446 | 424 | 1465 |
| Tool steel D2 — hardened | 60 | 697 | — | 2400 |
| HSS M2 — hardened | 64 | 800 | — | 2750 |
| Carbide insert | 72+ | 1500+ | — | — |