34CrNiMo6 (4340) Engineering Steel
1.6582
- EN1.6582
- EN34CrNiMo6
- AISI4340
- UNSG43400
Nickel-chromium-molybdenum quenched and tempered steel. Its high hardenability gives uniform QT properties even in large sections; preferred for heavily loaded parts requiring the highest combination of strength and toughness.

01Material Properties
- Rm 1000–1200 MPa (+QT), uniform in large sections
- High hardenability
- Very good toughness, also at low temperature
- Good fatigue strength
- Suitable for nitriding and induction hardening
02Applications
- Heavily loaded shafts and axles
- Large gears and pinions
- Crankshafts, connecting rods
- Turbine and compressor parts
- Aircraft landing gear and defence components
03Delivery Condition
- Quenched and tempered (+QT) or soft annealed (max. 248 HB).
04Heat Treatment
Typical values
- Soft annealing
- 650–700 °C; max. 248 HB
- Normalising
- 825–865 °C, air
- Hardening
- 830–860 °C; oil
- Tempering (QT)
- 540–660 °C, 1–2 h
- After QT (+QT)
- Rm 1000–1200 MPa, Rp0.2 ≥ 800 MPa (≤ 100 mm)
- Surface hardening
- Induction / flame; nitriding possible
Heat treatment cycle (schematic)
Tempering diagram (approximate)
Values are approximate and for information only; they vary with section size, heat and furnace conditions. Binding values are determined from the manufacturer’s data under laboratory conditions.
Have a material requirement?
Send us your specification, drawing or RFQ. Our team will review the requirement and identify a suitable supply option.
