The tenon is one hole in length, and the head of the standard one hole and a half in length.
On the working edge near the end mark the thickness of the tenon.
It is used to keep a tenon tightly fixed as in wheel spokes.
The tenon should be strong enough to share the strain with the shoulders.
The rule is that the tenon should be one-half the width of the rail, minus the groove.
A tenon should not be so large as to weaken the mortised piece.
A stub mortise-and-tenon is made by cutting only two sides of the tenon beam.
The width of the mortise is equal to the width of the groove, its length to the width of the tenon.
The joints may be made with dowels, or the mortise and tenon may be used, as desired.
This board should have a thickness equal to the piece to be cut from the side of the tenon.