7 mm spanners, also known as 7 mm wrenches, are hand tools used for tightening or loosening fasteners with a hexagonal or square-shaped head measuring 7 mm across. They typically have an open-end or a box-end configuration.

Open-end spanners have U-shaped jaws at each end, with one jaw accommodating the 7 mm fastener size. They provide a fixed grip on the fastener and are convenient for quick adjustments in tight spaces.

Box-end spanners, also known as combination spanners, have a closed-loop design with a 6-point or 12-point box-end on one or both ends. The box-end ensures a secure grip on the fastener, reducing the risk of rounding off the corners. Combination spanners often have a different size on each end, providing versatility for working with different fasteners.

7 mm spanners are commonly used in a variety of applications, such as automotive repairs, machinery maintenance, furniture assembly, and electrical work, where fasteners of this specific size are prevalent. They are compact, lightweight, and easy to handle, making them a valuable tool in many DIY projects and professional settings.