JL JLjthough we rarely think of it as such, the mortise-and-tenon joint was one of those technological achievements which, like the wheel or the computer, changed the world forever. The earliest known examples of woodworking were lashed or sewn together. This primitive joinery was inherently weak, and limited the size and complexity of wooden structures. It wasn't until the mor-tise-and-tenon joint appeared around 3,000 B.C. that people could take full advantage of wood as a building material. With this new joint, craftsmen made intricate furniture, huge buildings, and wagons and sailing ships capable of crossing great distances.
For all its applications, the mortise-and-tenon joint is deceptively simple. The mortise is just a cavity cut into one of the adjoining members. An end of the remaining member is shaped to make a tenon, which rests in the mortise. If the tenon fits the mortise properly, the joint will be almost as strong as if the two boards had grown together.
Only in the last 150 years have new materials and joining technol-ogy begun to supplant the mortise and tenon. But it still remains the joint of choice among many craftsmen for good, solid wooden framing. Once a tenon is pegged or glued in a mortise, it resists all four types of stress — tension, compression, shear, and racking — better than any other joint.
Mortise and Tenon Tips
Over nearly five thousand years of woodworking, many different types of mortise-and-tenon joints have evolved. (See Figure 5-1.) Some of these appear to be quite complex. However, none of them is particularly difficult to make as long as you follow these general guidelines:
■ Lay out both the mortise and the tenon with an awl and a marking gauge. It's especially important to scribe the shoulders of the tenon — this will help prevent the cutting tool from tearing the wood grain.
■ Make the mortise first, then fit the tenon to it.
■ Make sure the wood grain runs parallel to the length of the tenon; otherwise, the joint will be weak.
■ Make the mating surfaces of the mortise and tenon as smooth as possible for a stronger glue bond.
■ Fit the tenon to the mortise so it is snug, but not too tight. Leave some room for glue, and for wood expansion and contraction.
■ A tenon that is to be glued in a mortise should not be more than 3 inches wide or 3 inches long.
Was this article helpful?
Wonder No Longer About Things Like Designs, Tools And Safety. These Problems Among Others Will Be Covered In This E-Book. You Will Be Creating Great Wooden Works Of Art In Very Little Time At All! For The Beginning Woodworker, The Construction of Handcrafted Wood Creations Can Be a Daunting And Overwhelming Experience. Well, Not Anymore!