This hand tool is designed to tighten or loosen fasteners with a square socket drive of a specific size. It typically consists of a handle attached to a metal shaft with a precisely sized square recess at the end. A common configuration features a hollow shaft that allows it to work with longer fasteners.
The standardized sizing ensures compatibility with a wide range of screws, bolts, and nuts. This specific size is particularly prevalent in electronics, small appliances, and automotive applications where compact fasteners are common. Its use often simplifies assembly and disassembly processes, reducing the risk of damage compared to improperly sized tools. The evolution of these tools has led to variations like ratcheting mechanisms and interchangeable bits for increased versatility and efficiency.