642.5 Mohs = 6.3 HRC
| Mohs | HRC |
|---|---|
| 627.5 Mohs | 6.15 |
| 632.5 Mohs | 6.2 |
| 637.5 Mohs | 6.25 |
| 642.5 | 6.3 |
| 647.5 Mohs | 6.35 |
| 652.5 Mohs | 6.4 |
| 657.5 Mohs | 6.45 |
642.5 Mohs = 6.3 HRC
1 HRC ≈ 10.2 HV · 1 HRB ≈ 1.8 HV · 1 Mohs ≈ 0.1 HV — approximate; real conversions vary by material per ASTM E140