Torque Applied via a Wrench

Torque is directly proportional to the force applied to rotation, and is:

Also proportional to the distance from the center of rotation where the force acts

Applying a force at the farthest end of a lever arm is advisable in:

Getting the greatest possible torque

When a mechanic applies his maximum force but is unable to turn a difficult bolt:

A longer wrench may do the trick

This doesn’t increase the force he is able to apply, but:

Use of a longer lever arm for the same force does result in increased torque then and therefore, hopefully, better success in loosening the bolt

Unlike work, an object:

Does not have to be successfully rotated before a torque is said to have been applied