Definition
A small fastener with internal threads, designed to mate with the external threads of a bolt or screw to clamp parts together. In aviation maintenance, nuts come in many specialized forms — including self-locking, castellated, plain hex, and wing nuts — each chosen for the load, vibration, and access conditions of the application.
Plain English
The threaded piece that screws onto a bolt to hold parts tightly together. On aircraft, the type of nut used is chosen carefully so it won't shake loose in flight.
Context Anchor
Seen in aircraft maintenance, preflight inspection findings, and any discussion of bolts, hardware, and secured parts.
Derivation
Nut comes from an old word for a small hard object, originally the edible nut. The hardware meaning developed because early nuts were small, hard pieces that fit onto bolts.
Why Pilots Care
Loose or missing nuts can allow critical components such as engine mounts, control linkages, and landing gear to separate, directly affecting flight safety.
Intuition Check
Do not read nut here as food or slang. In aircraft maintenance, a nut is a threaded fastening part that works with a bolt or threaded shaft.
Example Sentence 1
The mechanic torqued the nut on the engine mount bolt to the value specified in the maintenance manual.
Example Sentence 2
Before flight, the pilot checked that the wheel nut was secure and had not backed off.