wedge, piece of wood or metal thick at one end and sloping to a thin edge at the other; an application of the inclined plane. It is employed in separating two objects from each other or in separating one part of a solid object from an adjoining part, as in splitting wood. The thin edge is applied to the surface of the solid or to the crack between two solids, and force is applied to the opposite thick edge. The ax, chisel, knife, nail, and carpenter's plane are wedges, and the cam is a rotating wedge.

In mechanics, a device that tapers to a thin edge, usually made of metal or wood, and used for splitting, lifting, or tightening, such as to secure a hammer head onto its handle. The wedge is considered one of the five simple machines. Wedges have been used since prehistoric times to split logs and rocks; for rocks, wooden wedges, caused to swell by wetting, have been used. In terms of its mechanical function, the screw may be thought of as a wedge wrapped around a cylinder.

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