Bridle Joint Calculator — Frame Joint Dimensions

A bridle joint is essentially an open mortise and tenon. One piece has a slot cut into the end (like a fork), and the other has a tongue that fits into it. It is used for frame corners and T-joints where the end grain is visible.

Bridle joints are reasonably strong, offering good glue surface area and mechanical resistance to racking. They are not as strong as a mortise and tenon but are easier to cut and suitable for light frames, picture frames, and garden structures.

Use a bridle joint when the end of the joint will be visible and you want a decorative look, when the frame members are the same size, or when you need a quick, reasonably strong frame joint. Mortise and tenon is stronger and better for furniture that takes heavy loads.