A wrench or spanner's 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's 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's the s… (More on Wrench)