Definition
A flat, angled surface cut along the edge or corner of a part where two surfaces would otherwise meet at a sharp 90-degree angle. Chamfers are commonly machined onto bolt ends, shaft ends, hole openings, and the edges of mating parts to ease assembly, remove sharp corners, and guide components into position.
Plain English
A small angled cut that bevels off what would otherwise be a sharp corner or edge.
Context Anchor
Seen in aircraft maintenance, sheet metal work, machining, and inspection of parts where sharp edges or hole edges must be shaped correctly.
Derivation
From the Old French 'chanfraindre,' meaning to bevel or cut off an edge. The word entered English as a machining and woodworking term for the angled surface left after such a cut.
Why Pilots Care
Chamfered edges on fasteners and mating parts make assembly easier, reduce the chance of cross-threading, and prevent stress concentrations at sharp corners that could lead to cracks.
Analogy
A chamfer is like the slight sloped edge on the corner of a wooden table after the sharp corner has been shaved down.
Intuition Check
A chamfer is not just damage or wear on an edge. It is an intentional angled edge made to a specified shape or size.
Example Sentence 1
The mechanic inspected the chamfer on the bolt end to make sure it would start cleanly into the threaded hole.
Example Sentence 2
Inspect the chamfer on the flange edge for any nicks that could start a crack under vibration.