644.5 Mohs = 6.32 HRC
| Mohs | HRC |
|---|---|
| 629.5 Mohs | 6.17 |
| 634.5 Mohs | 6.22 |
| 639.5 Mohs | 6.27 |
| 644.5 | 6.32 |
| 649.5 Mohs | 6.37 |
| 654.5 Mohs | 6.42 |
| 659.5 Mohs | 6.47 |
644.5 Mohs = 6.32 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