How do you convert hardness?
Hardness is measured on several scales: Rockwell C (HRC), Vickers (HV) and Brinell (HB). They measure the same property with a different indenter and load, so conversion is always an approximation (per ISO 18265 / SAE J417, for steel). Rule of thumb: HV ≈ HB up to ~450, and Rm ≈ 3.3 × HB for unhardened steel. For hard materials (>450 HB), use HV or HRC; Brinell is no longer reliable there.
Frequently asked questions
How much HV is 50 HRC?
About 513 HV. Conversely, 500 HV is roughly 49 HRC.
Why only an approximation?
Each method uses a different indenter and force. The conversion holds statistically for steel; other alloys deviate.
Can I derive strength from hardness?
For unhardened steel, Rm ≈ 3.3 × HB is a rough estimate. Above ~50 HRC that relationship is no longer linear.