51CrV4 (6150) Spring Steel
1.8159
- EN1.8159
- EN51CrV4
- AISI6150
- UNSG61500
Chromium-vanadium spring steel. High elastic limit, fatigue strength and toughness; the standard material for heavy-duty springs, torsion bars and hand tools.
01Material Properties
- Spring hardness 44–52 HRC (1300–1700 MPa)
- High elastic limit and fatigue strength
- Good toughness and hardenability
- Tempering stability up to 300 °C
- Suitable for hot forming
02Applications
- Leaf and coil springs (heavy vehicles)
- Torsion bars and stabilisers
- Hand tools (wrenches, pliers)
- Cutting and bending blades
- Cold forming tools
03Delivery Condition
- Soft annealed (max. 248 HB) or quenched and tempered (+QT); flat and round bar.
04Heat Treatment
Typical values
- Soft annealing
- 680–720 °C; max. 248 HB
- Hardening
- 830–870 °C; oil
- Tempering
- 400–500 °C, 1–2 h
- Spring hardness
- 44–52 HRC (1300–1700 MPa)
- Note
- Decarburisation reduces fatigue life; protective atmosphere
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.