Tenons

Tenons are a woodworking joint feature: a projection on the end of a piece (the rail or beam) that fits into a corresponding cavity called a mortise. Together they form a mortise-and-tenon joint, a traditional method for joining pieces at right angles or with other angles. Tenons are used in furniture, cabinetry, and timber framing for strong, stable joints that can be disassembled with pins or wedges or glued for permanence.

Anatomy of the joint: The projection (tenon) has cheeks on the sides and shoulders on the outside. The mortise is cut in the adjoining piece and receives the tenon. If the tenon shows on both sides of the work, it's a through tenon; if it is hidden on one side, it's a blind tenon. A haunched tenon adds a small shoulder at the end to resist twisting and provide alignment. A wedged or pegged joint strengthens and locks the assembly.

Variations and dimensions: Common variations include haunched tenons, sliding tenons, and stub tenons. The dimensions are chosen to preserve wood strength: the tenon width is often about one-third of the workpiece thickness; the length should fit the mortise depth with a little extra for bearing. Proper surface preparation, glue, and precise mating surfaces are essential for a tight joint.

Construction methods: Manufacturing involves accurate measurements and cutting the mortise and tenon with saws, chisels, a router, or a mortising machine. Joints may be glued and clamped, or finished with pegs or wedges if disassembly is desired.

History and use: Mortise-and-tenon joints have been foundational in traditional furniture and timber-frame construction, valued for mechanical strength and appearance. While newer fasteners exist, the mortise-and-tenon joint remains a standard skill for woodworkers.