Pound-foot (torque)
A pound-foot is a unit of torque. One pound-foot is the torque created by one pound of force acting at a perpendicular distance of one foot from a pivot point. Conversely one pound-foot is the moment about an axis that applies one pound-force at a radius of one foot.
The value in SI units is given by multiplying the following approximate factors:
This gives the conversion factor:
The name "pound-foot", intended to minimize confusion with the foot-pound as a unit of work, was apparently first proposed by British physicist Arthur Mason Worthington. However, the torque unit is often still referred to as the foot-pound, and sometimes more specified as "foot-pound of torque".
Similarly, an inch-pound is the torque of one pound of force applied to one inch of distance from the pivot, and is equal to of a pound-foot. It is commonly used on torque wrenches and torque screwdrivers for setting specific fastener tension.
