An open-end wrench is a type of hand tool used for gripping and turning nuts and bolts. It features a U-shaped opening at one or both ends, allowing it to fit over fasteners of various sizes. Open-end wrenches are commonly made from steel and are designed to provide a good grip, making them ideal for loosening or tightening fasteners in tight spaces. These wrenches come in various sizes, often measured in either metric or imperial units. They are part of a larger category of tools known as wrenches, which also includes box-end wrenches and adjustable wrenches. Open-end wrenches are popular among mechanics and DIY enthusiasts for their versatility and ease of use.