Definition
A flat, fine-toothed hand file with one flat face and one curved (half-round) face, used in aircraft sheet metal and woodworking repair to smooth and shape both flat surfaces and curved or concave edges.
Plain English
A hand file with a flat side and a rounded side, so the same tool can smooth straight edges and curved cut-outs.
Context Anchor
Seen in aircraft maintenance, especially when discussing hand tools used on wooden structures, plastic parts, fairings, or interior pieces.
Derivation
Named after cabinet makers, who originally used this style of file to shape the flat panels and curved edges of fine wood cabinets. The same shape proved useful in aircraft repair, and the name carried over.
Why Pilots Care
A pilot may not use this tool in flight, but understanding it helps when reading maintenance descriptions or discussing repairs to wooden or plastic aircraft parts.
Intuition Check
Cabinet file does not mean a storage cabinet or a computer file. In this context, file means a hand tool with cutting teeth used to shape material.
Example Sentence 1
The mechanic used a cabinet file to smooth the curved edge of the inspection hole he had just cut in the skin panel.
Example Sentence 2
After drilling out the rivets, a cabinet file removed the burrs from the aluminum skin.