Definition
A small, curved hand file with cutting surfaces at each end and a narrow, uncut middle section that serves as a grip. The bent shape and varied tip profiles (round, oval, knife-edge, pointed) allow the user to file inside contoured, recessed, or hard-to-reach areas where a straight file cannot work.
Plain English
A short, bent file used to shape or smooth metal in tight spots that a normal straight file can't reach.
Context Anchor
Seen in aircraft maintenance and engine repair when a mechanic is finishing or cleaning up small curved areas on metal parts.
Derivation
From the French 'rifler', meaning to scrape or graze. The name reflects the tool's action — a light scraping cut along curved or awkward surfaces — rather than the bold material removal of a straight file.
Why Pilots Care
Using the right file helps a mechanic remove only the needed material without damaging the shape of the part.
Intuition Check
Do not read “file” here as a paper or computer file. A riffle file is a small shaped hand tool for working metal.
Example Sentence 1
The technician used a riffle file to clean up a small burr inside a curved port on the cylinder head.
Example Sentence 2
After using the riffle file on the cylinder head, the mechanic checked the surface for flatness before reassembly.