Cold Heading Explained: How Most Fasteners Are Actually Shaped

Cold heading is the process that shapes the majority of the world's bolts, screws, and rivets: wire is fed into a heading machine and struck by dies at room temperature, displacing the metal to form the head in one or more forging blows, rather than machining a head out of round bar stock and cutting the excess away.

Why cold heading dominates high-volume fastener production

Cold heading is a forming process, not a subtractive one — no material is removed, so there's essentially no scrap from head formation, and cycle times are extremely fast (some multi-station headers produce hundreds of parts per minute). For standard fastener shapes produced in volume, this makes cold heading dramatically cheaper per piece than machining the same geometry from bar stock. It's the reason a commodity hex bolt costs a fraction of a similarly sized fastener machined to a custom print.

The grain flow advantage

Because cold heading displaces and forges the material rather than cutting through it, the metal's internal grain structure follows the contour of the head and shank rather than being severed by machining cuts. This continuous grain flow generally gives a cold-headed fastener better fatigue resistance and mechanical strength than a machined equivalent of the same alloy and diameter — one reason cold heading is the standard process even for many structural and high-strength fasteners, not just low-cost commodity parts.

What cold heading is good and less good at

• Good for: heads, flanges, and shank shapes achievable through progressive die stations — hex heads, socket heads, flange bolts, most standard screw head styles — produced in meaningful volume where tooling cost is amortized.
• Less suited for: very low quantities where die/tooling cost can't be justified, highly irregular or asymmetric geometries better suited to machining, and materials too brittle or too work-hardening-prone to cold form without cracking (some of these require hot heading or machining instead).

Tooling lead time is the real constraint on custom cold-formed parts

Because cold heading relies on progressive dies matched to the exact part geometry, a new custom cold-headed part requires tooling design and fabrication before production can start — this tooling lead time, not the forming process itself, is usually the longest part of a custom fastener development timeline. Send us your part drawing through our contact form and we can help estimate whether cold heading is suitable and roughly how much tooling lead time to plan for.