A Stronger Miter
Reinforcing with a mortise and tenon locks the pieces in perfect position and adds strength to an otherwise weak joint
Seth Janofsky shows how to lay out and construct a tenoned miter joint. Accurate layout is critical. The mortised piece isn’t so difficult, but making the tenon fit the mortise takes some work. If all goes well, assembling this sturdy joint will be a breeze.
From Fine Woodworking #175