mortice

Mortice (British spelling) or mortise (American spelling) is a cavity cut into a piece of wood to receive a projecting part, most commonly a tenon, in a mortise-and-tenon joint. The mortise and tenon joint is valued for its strength and simplicity, providing resistance to shear and pulling forces when the tenon fits securely within the mortise.

The term derives from Old French mortaise, meaning a drilled or bored hole, reflecting the traditional woodworking method of removing waste material to form the socket. In practice, mortises are sized to match the corresponding tenon, and joints are often reinforced with glue and, sometimes, pins or wedges.

Common types include the through mortise, which runs completely through the workpiece, and the blind (or closed) mortise, which stops before exiting the opposite face. A haunched mortise incorporates a shoulder and a haunch to resist twisting and improve alignment. Other variations are designed to suit different timber sizes and load requirements.

Techniques to create a mortice range from traditional hands-on methods to powered equipment. Marking gauges establish precise boundaries, followed by removing waste with chisels, saws, or boring tools. A hollow-chisel mortiser or drill press can speed the process, while final flattening and squaring are done with chisels. Fit is checked dry before applying glue in suitable joints; a snug fit is crucial for joint strength.

Applications are widespread in furniture, timber framing, and door hardware. In doors, the term also refers to the cavity that receives a lock or latch mechanism. The mortice-and-tenon joint remains a fundamental technique in traditional and contemporary carpentry for its durability and simplicity.