Definition
A cold-forming manufacturing process in which a slug of soft metal is placed in a die and struck with a punch under high pressure, causing the metal to flow and squeeze upward around the punch to form a thin-walled, seamless part.
Plain English
A way of making metal parts by hitting a small piece of soft metal hard enough that it squishes and flows into the shape of a mold, forming a one-piece hollow part with no seams.
Context Anchor
Seen in aircraft maintenance and manufacturing discussions when describing how certain metal aircraft parts are made.
Derivation
Extrusion comes from the Latin extrudere, meaning 'to thrust out.' Impact extrusion adds the idea that the metal is thrust out by a sudden blow rather than slowly squeezed, which is how the part takes its shape.
Why Pilots Care
Produces strong, lightweight, seamless metal parts that reduce weight and eliminate weld failure points in critical aircraft systems.
Analogy
It is a little like pressing soft clay into a mold with a sudden hard push, except the material is metal and the force is much greater.
Intuition Check
Impact extrusion does not mean a part was damaged by an impact. Here, “impact” describes the force used to manufacture the part.
Example Sentence 1
The hydraulic reservoir was made by impact extrusion, giving it a seamless aluminum body that resists leaks.
Example Sentence 2
Mechanics prefer impact-extruded cylinders in hydraulic systems because they contain no seams that could leak under flight loads.