Newton-Metres to Pound-Feet: Torque Without Guesswork

Torque specs are where workshop manuals from different decades and continents collide.

The conversions

lb·ft = N·m × 0.737562 N·m = lb·ft × 1.355818 kgf·m = N·m × 0.101972

Rule of thumb: N·m × 0.74 = lb·ft, and lb·ft × 1.36 = N·m.

Common fastener torques

Fastener	N·m	lb·ft
Bicycle stem bolt	5	3.7
Spark plug (14 mm)	25	18.4
Car wheel nut	110	81.1
Truck wheel nut	450	331.9

Small fasteners are often specified in pound-inches (lb·in), which is one twelfth of a pound-foot. Reading 60 lb·in as 60 lb·ft would apply twelve times the intended load — a reliable way to snap a bolt. Use the pound-inches converter when the spec is small.

lb-ft or ft-lb?

Strictly, torque is force × distance, so pound-force foot (lbf·ft) is correct, and energy is foot-pound (ft·lbf). In practice manuals use both spellings for torque interchangeably. The numbers are identical; only the pedantry differs. If a figure appears in an engine spec, it is torque.

Why the pattern matters as much as the number

Cylinder heads, wheels and flanges are tightened in a sequence — usually crosswise, in two or three increasing stages. Torquing one bolt fully before its neighbours distorts the joint even if every final reading is correct.

Also worth knowing:

• Torque-to-yield bolts are designed to stretch permanently and must be replaced, not reused.
• Angle-torque specs ("30 N·m plus 90°") need a gauge, not a wrench.
• Lubrication changes everything. An oiled thread reaches a much higher clamping force at the same torque reading. Follow the manual's dry/wet instruction.

Related conversions

• Pound-feet to newton-metres
• Kilogram-force metres to newton-metres
• All torque units