Definition
A tubular part designed to fit over a shaft, pin, bolt, cable, or another component, typically used to provide a bearing surface, protect the inner part from wear or damage, act as a spacer, or join two parts together.
Plain English
A hollow cylinder that slides over something else — like a shaft or a wire — to protect it, support it, hold it in place, or connect it to another part.
Context Anchor
Seen in aircraft maintenance manuals, parts lists, and inspections involving cables, tubes, wiring, bushings, and other fitted parts.
Derivation
From Old English 'slefe', meaning the part of a garment that covers the arm. The mechanical sense follows the same idea — a tube that wraps around and covers something inside it.
Why Pilots Care
A damaged, missing, or incorrectly installed sleeve can let a part move, rub, wear, or come loose, which can affect the reliability of the aircraft system it supports.
Analogy
Think of it like the sleeve on a shirt: a hollow tube that slips over the arm. A mechanical sleeve does the same thing, slipping over a shaft or wire to cover, protect, or support it.
Intuition Check
Do not think of sleeve only as clothing. In aircraft maintenance, a sleeve is a fitted tube-like part used with another part.
Example Sentence 1
The technician installed a new bronze sleeve on the shaft to provide a smooth bearing surface.
Example Sentence 2
A scored sleeve requires replacement or honing to restore proper piston fit and prevent compression loss.