Final answer:
A wrench is the fastening tool used to turn nuts and bolts. Mechanics sometimes use a length of pipe over the handle of a wrench to provide extra leverage when removing a tight bolt.
Step-by-step explanation:
The fastening tool used to turn nuts and bolts is called a wrench. A wrench provides grip and mechanical advantage in applying torque to turn a nut. When trying to remove a very tight bolt, mechanics sometimes put a length of pipe over the handle of a wrench to provide extra leverage.