Joining end grain to long grain with the king of joints.

A mortise and tenon is one of the most ubiquitous and useful means to join wood together. Primarily used in solid wood woodworking to join end grain to edge grain, or long grain, it is a time-honored and proven technique. An M&T is, at its most basic, a peg fit into a hole. It accommodates the dynamic movement of wood fibers and creates a super strong joint. Because it has been around so long, and due to the variety of tools and techniques employed to form these workshop workhorses, there are several variations on this simple theme. To kick off our series on the mortise and tenon joint, we've compiled Master Woodworker Ian Kirby's list of 10 rules for making perfect M&Ts.

Mortise and Tenon Rules
1. Hidden mortises should penetrate about halfway into a stile.
2. Create balanced joints.
3. Structural shoulders resist stress.
4. Cosmetic shoulders hide the joint.
5. At the end of a stile, leave a horn to resist splitting.
6. Don't undercut.
7. The completed joint should slide together with moderate hand pressure.
8. Accurate geometry is the key to effective joinery.
9. With stopped tenons, always cut them 1/16-inch short of the end wall.
10. Use a sufficient amount of glue on the joint, but avoid over gluing.