Cold Forging
Cold forging shapes metal at room temperature using high-pressure dies, giving excellent dimensional accuracy, surface finish and work-hardened strength with almost no material waste. It is widely used for fasteners, pins, shafts and small precision parts.
What it is
Wire or slugs are pressed through a series of dies (heading, extrusion, upsetting) on multi-station formers or presses. Because the metal is not heated, there is no scale and tolerances are tight.
Cold forging suits ductile steels, aluminium and copper alloys in high volumes, often replacing machining from bar.
Typical applications
- Bolts, screws and rivets
- Pins, shafts and studs
- Spark plug and automotive parts
- Electrical terminals
- Ball studs and fittings
Suitable materials
- Low-carbon and boron steels (cold heading grades)
- Alloy steels
- Aluminium alloys
- Copper and brass
- Stainless steel (selected grades)
Points to consider
- Requires cold-heading quality material.
- Very high volumes needed to justify tooling.
- Complex shapes may need warm forging.
- Work hardening increases strength but may need annealing between stages.
Frequently asked questions
What are the advantages of cold forging?
High accuracy, good surface finish, work-hardened strength and minimal material waste, at very low cost per part in volume.
What parts are cold forged?
Fasteners, pins, shafts, terminals and small automotive parts are typical.
Can stainless steel be cold forged?
Yes, selected grades can, though they need more force than carbon steel.