Types of Joints Used in Joinery
Though there are many more types of joints used in joinery than I could describe in detail, I figured I would touch on some of the main ones. The first and simplest joint used in just about any type of joinery job is the butt joint. This type of joint is when two members are butted up against one another, such as if you placed a tabletop on top of four legs with the top board merely rested on the legs. This joint is weakest when it is just glued, but can also be reinforced through various methods (this joint is still comparatively weak though). One method of reinforcement you have probably seen before is with wooden dowels being placed in holes aligning between the two members. Also, nailing the two members together is a common way of reinforcing this type of joint.
A type of joint that would be common within Japanese joinery or other situations where a strong joint is necessary outside of traditional carpentry methods is the mortise and tenon joint. The two members used in this joint involve one with a hole called a mortise and another with a narrowed protrusion called a tenon. The tenon is placed inside the mortise and can be locked into place with glue, pins, or a wedge.
Image Source: Banalities
One really interesting way in which this joint is utilized is by placing wedges partially into the edge of the tenon. With two of these wedges in place, when the tenon reaches the back of the mortise they work two split the tenon in two places, causing it to expand on one plane and lock the joint in place. This is sometimes referred to as a suicide joint because once the joint is assembled and tenon fully wedged, there isn’t really much you can do to remove it.
The last type of joint I want to talk about in this post is the dovetail joint. It is another fairly common type of joint that you might have seen on the side of a drawer or wooden house or even used in one of your own joinery projects. One board has a set of pins cut into the edge and the other has a set of tails cut into the other. These features are generally trapezoidal in shape and after assembly don’t even need any mechanical fasteners. There are certain dovetail joints that help hide the appearance of the joint after assembly, but in contemporary construction they are generally regarded as an attractive feature and are not covered with a veneer.
There is still clearly a lot for me to learn about joinery jobs and the different tools and joints used within them, but this seems like a good place to stop until next time.