Wrench:

A wrench is a commonly used installation and disassembly tool. It is a hand tool that uses the principle of leverage to turn bolts, screws, nuts and other threaded fasteners of bolts or nuts. Wrenches are usually made of structural steel made of carbon or alloy materials.

Open-end wrench,torx head key wrench,both ends wrench,hexagon L-key wrench.

A wrench usually has an opening or a hole at one or both ends of the handle for clamping a bolt or nut. When in use, an external force is applied to the handle along the direction of thread rotation to turn the bolt or nut.