Definition
A unit of torque equal to the rotational force produced by one pound of force applied at the end of a lever one inch long, measured perpendicular to the lever. Commonly used to specify tightening values for small fasteners in aircraft maintenance.
Plain English
A way to measure how tightly something is twisted or turned. One inch-pound is the twist you get when you push with one pound of force on a wrench that is one inch long.
Context Anchor
Seen in aircraft maintenance manuals, torque tables, and torque wrench settings for small fasteners and parts.
Derivation
The name combines the two units involved: 'inch' (the length of the lever arm) and 'pound' (the force applied). Putting them together describes the twisting effect those two values produce.
Why Pilots Care
Correct inch-pound values prevent under- or over-tightening that could cause fastener failure, stripped threads, or loss of control in flight.
Analogy
Picture a wrench that is one inch long. If you push on the end with one pound of force, you are applying one inch-pound of torque.
Intuition Check
An inch-pound is not simply an inch or a pound by itself. It is a measure of turning force made from both force and distance.
Example Sentence 1
The maintenance manual specified that the instrument panel screws be torqued to 15 inch-pounds.
Example Sentence 2
The maintenance manual specifies 80 inch-pounds for the elevator hinge bolts on this model.