lbft

lbft, often written lb-ft, is a unit of torque in the imperial system. It expresses the turning effect produced by a force applied at a distance from a pivot. One pound-force acting at a radius of one foot generates one pound-foot of torque.

Symbol and conversions: pound-foot torque is commonly abbreviated lb-ft or lb ft; in some contexts it is written as ft-lbf. In engineering practice, 1 lb-ft equals 12 in-lbf and equals about 1.3558 N·m. The latter is the SI unit of torque.

Context and usage: Torque specifications for fasteners, engines, and rotating machinery are frequently given in lb-ft. Torque wrenches often display lb-ft or in-lb; automotive manuals may cite ranges such as 20–80 lb-ft. When converting to metric, use 1 lb-ft ≈ 1.35582 N·m.

Notes: The same dimensional form can appear in energy/work as ft-lbf; context usually distinguishes torque from energy.