Newton metre

From Wikipedia, the free encyclopedia

Newton metre is the unit of moment in the SI system. It is abbreviated N m or N·m, and sometimes hyphenated newton-metre. It is a compound unit of torque corresponding to the torque from a force of one newton applied over a distance arm of one metre.

While a newton metre is dimensionally equivalent to a joule, the SI unit of energy and work, in a newton metre, the force and the distance arm are normal to each other, while in the joule, force and distance are co-linear. Another fundamental difference between the two is the fact that work is a scalar quantity, expressed as dU=F•dr, whereas the moment of a force or torque is defined as a cross product and as such is a vector quantity.

[edit] Conversion factors

1 metre kilogram-force = 9.8065 N·m
1 centimetre kilogram-force = 98.0665 mN·m
1 foot-pound force (often "foot-pounds") = 1 pound-force foot (often "pound-feet") = 1.3558179 N·m
1 inch ounce-force = 7.0615518 mN·m