In the quenched and tempered (also called "heat-treated" or "hardened and tempered") condition, 42CrMo achieves its optimal balance of strength and toughness. Properties vary with the precise tempering temperature. Here is a table showing typical values for medium-strength tempering:
| Property | Typical Value (e.g., Tempered at ~550-600°C) | Test Standard |
|---|---|---|
| Tensile Strength (Rm) | 900 - 1100 MPa | ISO 6892-1 / ASTM A370 |
| Yield Strength (Rp0.2) | 650 - 850 MPa | ISO 6892-1 / ASTM A370 |
| Elongation at Break (A) | ≥ 12 - 16 % | ISO 6892-1 / ASTM A370 |
| Reduction of Area (Z) | ≥ 45 - 55 % | ISO 6892-1 / ASTM A370 |
| Impact Energy (KV) | ≥ 40 - 60 J (at 20°C) | ISO 148-1 / ASTM A370 |
| Hardness | 270 - 320 HBW | ISO 6506-1 / ASTM E10 |
Note: Higher tempering temperatures yield lower strength/hardness but higher toughness/ductility, and vice-versa. The exact values are guaranteed by the producer's test certificate for the specific batch.