Eh, almost. I'm a mech E, can't help it. The definition of torque (a measurement of rotational force) is force 'crossed' (the mathematical cross product) with distance, i.e, the force times the perpendicular distance from the point of application to the center of rotation. In general use, the length of the useful part of the wrench you're grunting on. The appropriate unit is lbf-ft -- pounds force times feet. A foot-pound, abbreviated ft-lb, is technically a measure of energy (which is force times a distance), not simply force itself, which torque is the rotational equivalent of. These are commonly swapped. A useful extension is the relationship of torque to horsepower. Hp is a measure of work, which is force that is allowed to cover a distance in time, and is expressed as force per unit time, so hp tells you that so much torque (force) is acting over a certain distance, in a given amount of time. One hp is 550 foot-pound force per minute. From this it falls out that if you are grunting on a wrench and not turning the bolt, you may be applying torque (force to induce rotation), but since no distance has been covered, technically you've done no work and exerting precisely zero power. And yeah, 775 lbf-ft is a lot! I have this big honking 3/4" drive torque wrench with a 3ft long handle that I think hits 400, and it's absurdly huge. Regards, Huntsman
