In mortise-and-tenon joinery, what is the role of the mortise?

• A. A hole that receives the tenon.
• B. A decorative groove.
• C. A type of glue.
• D. A metal fastener.

Answer: (A)

Mortise-and-tenon joinery hinges on a hollow cut into one piece that receives a projecting tongue from the adjoining piece. The mortise is that hollow slot, and its role is to accept the tenon, forming a strong, aligned connection. When the tenon fits snugly inside, the joint resists pulling apart and helps keep the frame square. Glue can be used to add strength and pegs or wedges may reinforce the joint, but the essential function of the mortise is to house the tenon. It is not a decorative groove, not glue itself, and not a metal fastener.