Question

An old shade-tree mechanic trick for removing a stubborn bolt is to slip a long pipe over the handle of the wrench, then apply a force to the end of the pipe opposite the bolt.
Why is this effective? What problems might this technique cause?

Answer 1

Answer: long pipe is used to increase torque and reduce force needed.

Explanation: A torque is needed to open bolt. torque = F·r, if

R increases, Force F needed to open bold is smaller.

Problem is a worn bolt may break down. It sometimes I send useful to heat bolt instead using too much power.