Mortise and Tenon joint

 

A mortise and tenon joint is used to join pieces of wood, usually at an angle of 90°.

 

The mortise is the hole and the tenon is the pin. The tenon, or pin, is inserted into the mortise, or rectangular hole.

 

The mortise hole is exactly the same size as the tenon and both fit together to form a very strong joint. The joint may be glued, pinned or wedged to lock it in place.