Hardness conversion HRC, HV, HB: chart and converter
Published October 5, 2026 — the Rockwell C, Vickers and Brinell correspondence for steels from 20 to 65 HRC, a converter, what each test measures and why a conversion does not replace a measurement.
In short: HRC, HV and HB do not measure the same thing (penetration depth for Rockwell, indent size for Vickers and Brinell). You move between them with tables built from comparative tests (ASTM E140, ISO 18265), valid for one material type. For non-austenitic steels: 40 HRC ≈ 392 HV ≈ 371 HB, 60 HRC ≈ 697 HV ≈ 654 HB. A conversion gives an order of magnitude; acceptance is done in the scale specified on the drawing.
1. HRC ↔ HV ↔ HB conversion chart (steels)
Correspondences from the ASTM E140 tables for non-austenitic steels (carbon and low-alloy steels). Brinell measured with a tungsten carbide ball.
Below 20 HRC, the Rockwell C scale is no longer suitable: measure in Rockwell B (HRB), Vickers or Brinell. For structural steels, the guaranteed properties are yield and tensile strength, detailed in the S235, S275, S355 memo.
2. HRC, HV, HB converter
Enter a value and its scale: the other two are calculated by linear interpolation between the chart rows, from 20 to 65 HRC. Outside that range, the converter gives no answer rather than extrapolate.
3. What each test measures
This difference in principle is what makes conversions approximate: two steels with the same Vickers hardness can give slightly different HRC depending on their structure and treatment.
4. On the drawing and at acceptance
- Specify a range, not a value: "58–62 HRC" can be checked, "60 HRC" leaves the shop without a tolerance.
- Choose the scale to suit the part: HRC for a through-hardened steel, HV (often at low load) for a thin case-hardened or nitrided layer, HBW for a raw part or cast iron.
- Do not accept on a converted value: if the drawing asks for HRC, the certificate must give measured HRC. Conversion is for comparison, not acceptance.
- In SOLIDWORKS, hardness goes into a custom property picked up by the title block, like the material: see SOLIDWORKS numbering and properties.
5. FAQ
How do you convert HRC to HV?
With a standard conversion table (ASTM E140 or ISO 18265), not a formula: for example 40 HRC ≈ 392 HV and 60 HRC ≈ 697 HV for a non-austenitic steel. Between two table rows, linear interpolation gives an order of magnitude.
What is 50 HRC in Brinell?
About 481 HB (tungsten carbide ball) and 513 HV, per the ASTM E140 tables for steels.
Can these conversions be used for stainless steel or aluminium?
No. This table applies to non-austenitic steels. Austenitic stainless steels (304, 316), aluminium, copper or cast irons have their own tables, because they behave differently under the indenter.
Why is a hardness conversion approximate?
Each test loads the material differently (depth for Rockwell, indent size for Vickers and Brinell, different loads). The tables come from comparative tests on steels: they give an average correspondence, not an equality. For acceptance, measure in the scale required on the drawing.
What does HBW mean?
A Brinell hardness measured with a tungsten carbide ball (W for wolfram). It is the only ball allowed by ISO 6506; the old HB or HBS notation also covered steel balls.