Definition
A metalworking process in which the head of a fastener, such as a rivet or bolt, is formed by upsetting (compressing and reshaping) the end of a metal rod at room temperature, without heating the material. The cold-working action increases the strength and hardness of the formed head through work hardening.
Plain English
A way of forming the head of a rivet or bolt by squeezing the end of a metal rod into shape while it is still cold, instead of heating it first. Forming it cold also makes the head stronger.
Context Anchor
Seen in aircraft maintenance, structural repair, and manufacturing discussions about rivets, bolts, screws, and other metal fastening parts.
Derivation
‘Cold’ refers to forming the metal at room temperature rather than heating it. ‘Heading’ refers to forming the head of the fastener. Together: forming the head while the metal is cold.
Why Pilots Care
Cold-headed rivets and bolts are stronger than they would be if simply cast or machined, because the cold-forming process work-hardens the metal. Knowing this helps a pilot or mechanic understand why aircraft fasteners are reliable under load and why substitutes from a hardware store are not acceptable.
Analogy
It is like flattening the end of a soft metal pin with a tool to make a wider cap, except the aircraft process is controlled and done to precise standards.
Intuition Check
Cold heading does not mean pointing the aircraft toward cold weather. Here, heading means forming the head of a metal part, and cold means the metal is shaped without being heated first.
Example Sentence 1
The aircraft rivets in the fuselage skin were produced by cold heading, which gave them greater strength than untreated metal.
Example Sentence 2
During the pre-installation inspection, the mechanic verified that the bolts had been produced by cold heading as specified in the parts manual.