Definition
A raised ring, flange, or band fitted around a shaft, pipe, or fitting to limit movement, hold a part in position, reinforce a joint, or provide a sealing or stop surface.
Plain English
A ring that fits snugly around something to keep parts in the right place, stop them sliding, or strengthen the area where two parts meet.
Context Anchor
Seen in aircraft maintenance descriptions, parts manuals, and inspections of mechanical assemblies.
Derivation
From the Latin 'collare,' meaning 'band for the neck.' Just as a collar wraps around a neck to hold or restrain, a mechanical collar wraps around a shaft or fitting to hold it in position.
Why Pilots Care
Secures critical moving parts against unwanted shift that could affect flight controls or landing gear operation.
Intuition Check
Do not read collar here as clothing. In aircraft use, it means a ring-shaped hardware piece fitted around another part.
Example Sentence 1
The mechanic installed a new collar on the control rod to keep it from sliding out of position.
Example Sentence 2
During inspection, verify the landing gear torque collar remains tight and undamaged.