YAMAMOTO - Hardness Test Block
Brand: Yamamoto - Japan
Rockwell Blocks (64mm diameter)
| Scale | Nominal Hardness Value | Variation |
| HRA | 56, 65, 71, 75, 78, 81, 83, 85, 87 | +0.3 |
| HRB | 32, 42, 52 | +0.5 |
| HRB | 62, 72, 82, 90, 95, 100 | +0.4 |
| HRC | 10, 20, 25, 30, 35, 40 | +0.15 |
| HRC | 45, 50, 55, 60, 62, 64, 67, 70 | +0.1 |
| HR15N | 75, 80, 85, 87, 90, 92 | +0.45 |
| HR30N | 41, 50, 60, 67, 73, 78, 81, 83 | +0.45 |
| HR15T | 78, 82, 87 | +0.5 |
| HR30T | 32, 42, 52, 62, 72, 78 | +0.5 |
| HRE | 90 | +0.5 |
| HRL | 92, 118 | +0.5 |
| HRM | 67, 107 | +0.5 |
| HRR | 105, 123 | +0.5 |
| Scale | Nominal Hardness Value | Variation |
| HRC | 20, 25, 30, 35, 40, 45 | +0.15 |
| HRC | 50, 55, 60, 62, 64, 67 | +0.1 |
| Scale | Nominal Hardness Value | Variation |
| HBW30 |
150, 180, 200, 229, 250, 300, 350, 400, 450, 500, 550, 600 |
+0.7% |
| HBW5 | 100, 125 | +0.7% |
| Scale | Nominal Hardness Value | Variation |
| HV |
100, 200, 300, 400, 500, 600, 700 800, 900 |
+2.5% |
