chair leg joint
This is a double shouldered bridle joint (also called a Sam Maloof chair joint). After fitting and gluing the joint, 3/8" steel dowels (sheet metal screws) are driven into the joint and the heads are plugged. These pictures are of 4 different chairs, 2 in cherry and 2 in black walnut.
shouldered and wedged through tenons
below: the joint before assembly - the shoulder adds another whole set of bearing surfaces.
A solid wood tabletop (this one is over 30 in. across the grain) will expand and contract almost 1/2" seasonally. To accommodate this movement and hold the top down flat, I use a sliding dovetail on a cross rail that, in this case, is screwed down to the pedestal base.
To carry the weight of a loaded table to the floor without splitting this leg joint requires some heavy reinforcement. With both the pedestal table (above) and the trestle table (left) I use pinned tenons at the top of the joint and a hardwood strip let into the leg (illustrated above) with #12 screws in each end.
For a trestle table (above left in white oak and at left in red grandis) I capture the trestle in a shouldered slot made in the legs. The slot is slightly longer than the trestle width to accomodate seasonal movement.
When a leg or post joint terminates at a right angle I will inevitably use this joint. At left, in a mother's (armless) rocking chair in hard maple.
to carry the stresses on a piece without stretchers, I started putting an interior shoulder at the end of my wedged through tenons.
When a joint is made at the end of two wider boards and the joint needs to be strong, the dovetail joint is the best.