What's the difference between horsepower and torque?

Question

Whenever I check an electric motor's statistics, I NEVER see anything regarding torque. I see hp, rpm, watts, shaft size, but NO TORQUE. Can someone please tell me what torque is and how it relates (if it relates) to the motor's strength and ability.

Answer 1

Torque might not be on the nameplate, but every motor has a torque spec. If the load requires more torque than the motor is capable of delivering, it will stall. A motor has a torque-speed curve, so hard to give a single number for a nameplate.

A prior answer saying torque and power aren't related is wrong. The power a motor is delivering at an instant is the torque multiplied by the speed. The peak power is at a medium speed (between stalled and full no-load speed), but I'm not sure if the nameplate power is that peak or something else. Marketing of many consumer devices uses an inflated power a motor could never deliver continuously (see http://users.goldengate.net/~kbrady/motors.html).

Answer 2

Torque is how much power the motor has at fire up...what kind of resistance it can stand and still start turning. HP is a measure of its power at a specific revolution...The two are not related...a high hp motor might have very poor torque when firing up. High torque motors are usually 3 phase to get that added punch.

Answer 3

The electrical horsepower is used by the electrical industry for electric motors and is defined to be exactly 746 W (at 100% efficiency).
The formulas are in the Ugly's book or click here
http://en.wikipedia.org/wiki/Horse_power#Electrical_horsepower

Answer 4

dont need torque specs on an electric motor.

Answer 5

Horsepower is a measurement used to rate power of an engine.
Torque: The force that acts to produce rotation as in an automotive vehicle. The tightening of nuts and bolts.....