Definition
A gear tooth whose sharp end edge has been ground or cut away at an angle to form a small bevel. The chamfer removes the abrupt corner where the tooth ends, allowing gears to mesh together more smoothly when they are slid into engagement.
Plain English
A gear tooth with its end corner shaved off at a slant so it slides into the matching gear cleanly instead of catching on a sharp edge.
Context Anchor
Seen in aircraft maintenance descriptions, especially when inspecting gears, starter drives, splines, or other parts that have interlocking teeth.
Derivation
Chamfer comes from the Old French chanfraindre, meaning to cut off an edge at an angle. In machining, a chamfer is any small bevel cut on a corner. Applied to a gear tooth, it tells you the end of the tooth has been deliberately angled rather than left square.
Why Pilots Care
Smooth meshing prevents gear damage that could cause engine power loss or propeller control issues.
Intuition Check
Do not assume a chamfered tooth is a worn-down or broken tooth. In this term, chamfered means the angled edge was deliberately made as part of the design or repair specification.
Example Sentence 1
The accessory drive gears use chamfered teeth so they engage smoothly without grinding when the engine is started.
Example Sentence 2
Chamfered teeth allow the starter drive gear to engage the flywheel without binding during engine start.