Wrench, as a common hand tool, is widely used in various maintenance and assembly work. Its main function is to help the user tighten or loosen the connecting parts such as nuts and bolts by providing leverage. The design of the wrench is simple and ingenious, making this tool indispensable in various industrial fields and household daily use.

There are many kinds of wrenches, common open wrenches, ring wrenches, socket wrenches and adjustable wrenches. Open wrenches and ring wrenches are usually used for nuts and bolts of a specific size. Open wrenches have two openings opposite each other and can be used to clamp both sides of the nut, while ring wrenches are used to enclose the nut with a closed ring to provide better grip. The socket wrench is used with different specifications of the sleeve, suitable for more narrow space operation. Adjustable wrench because of its adjustable characteristics, suitable for a variety of different sizes of nuts and bolts, it is very convenient to use.

Wrenches are usually made of steel or alloy to ensure their durability and compression resistance in high-intensity use. In some professional applications, in order to prevent damage to the parts being operated, the contact surface of the wrench may also be specially treated to increase friction or designed to a specific shape in order to better adapt to nuts and bolts of different structures.

When using a wrench, the correct method of operation is crucial. The user should ensure a good fit between the wrench and the connector to prevent slippage or damage. In addition, the applied force should be uniform and moderate, too much force may cause the nut or bolt deformation, and too small force may not achieve the ideal tightening effect.