A wrench is a commonly used installation and removal tool. It is a hand tool that uses the principle of leverage to turn bolts, screws, nuts, and other threads to hold the opening or sleeve of the bolt or nut. Wrenches are usually made of structural steel made of carbon or alloy.
The wrench usually has openings or sleeve holes for holding bolts or nuts at one or both ends of the handle. When using the wrench, an external force is applied to the handle along the direction of thread rotation to turn the bolt or nut.