wedge

A wedge is a simple machine that tapers to a thin edge. It is thick at one end and narrows to a sharp edge, and it converts force applied to the thick end into a separating force along its length. Wedges are widely used to cut, split, or lift objects, and they also appear in everyday items such as doorstops and shims. In geometry, a wedge is often described by the same tapering shape: two inclined faces meet at a sharp edge.

Mechanics: When the wedge is driven into a material, the faces exert pressure on the contact surfaces. The force applied to the thick end translates into a component that pushes the material apart along the wedge's length. The mechanical advantage depends on the wedge angle and the friction between surfaces; sharper wedges concentrate force but require more displacement to seat. Material choice and manufacturing affect durability and efficiency.

Types and applications: The simplest form is a single wedge; a double wedge has two inclined faces meeting at a central edge. More complex wedges combine multiple blades. Common examples include axe blades and knives, chisels, door wedges, and wooden shims used for leveling. Wedges are used in construction, logging, metalworking, and machining as cutting tools, splitters, fasteners, or alignment pieces.