A wrench or spanner is a tool used to provide a mechanical advantage in applying torque to turn bolts, nuts or other items designed to interface with a wrench. In American English, wrench is the standard term, while spanner refers to a specialized wrench with a series of pins or tabs around the circumference. (These pins or tabs fit into the holes or notches cut into the object to be turned.) The most common shapes are called open-end wrench and box-end wrench. In British English, spanner is th… (More on Wrench)