The Dowel joint
This is when two pieces of wood are joined using a dowel reinforcement. It’s an efficient and cost-effective solution for modern manufacturers, thus it’s quite commonly used in factory-made furniture. Think your old friends at a certain unnamed Swedish furniture conglomerate.
The Mitre joint
A beautifully simple but fairly weak joint which is commonly used in tables, picture frames and other light applications. It consists of two pieces of wood, bevelled on the end/edge (usually at 45°), and glued together to create a right angle. This joint has the advantage of incredible aesthetics but the disadvantage of low strength threshold.
The Halved joint
Another clean, aesthetically pleasing joint with, sadly, limited applications and limited strength. Two pieces of wood are placed at an intersection (X position), with identical cutouts in the centre of each piece to enable a flush over-lap. A handy joint used in cabinetry as partitions, as well as in Torsion Boxes.
The Housing joint
Also known as a Dado or Trench joint, this is when a through or stopped section is cut out against the grain of one piece, in order to fit into another. It’s a very common, straightforward joint used extensively in carpentry, especially for shelving.
The Groove joint
Similar to a Housing joint, but is differentiated by the piece of wood being cut with the grain instead of against it. Like the Housing joint, it can be cut through or stopped, meaning it’s ends are left open on both sides or closed on one side. Increased strength and stability would be one reason to make a Groove or Housing joint stopped.
The Mortise and Tenon joint
A common traditional woodworking joint with historic origins, the Mortise and Tenon is significant in the simplicity of it’s design and the strength it provides. There are a seemingly endless array of types, mostly a variation of the Mortise (hole) or Tenon (tongue), all which provide varying levels of stability. This joint can’t be underestimated, and is a beautiful example of form and function in one. You will most likely have multiple examples of furniture with this joint in your home right now!
The Finger joint
An easy one to grasp due to the name, this joint is made from two pieces of wood which have a series of small, complementary cut-outs made on the ends which interlock to make a right angle. This joint has increased strength and stability due to the two-way pressure load, and can also add hugely to the aesthetic of the piece.
The Dovetail joint
Perhaps the signature joint in furniture design and fine carpentry, the Dovetail has it all; strength, aesthetic and endurance. Similar in principle to the Finger joint, the Dovetail joint differentiates itself via the complementary cut-out “fingers” being diagonally cut and in a number of configurations, depending on the type. These include the Through Dovetail, the Half-Blind Dovetail, the Secret Mitred (or Full-Blind) Dovetail, the Secret Double-lapped Dovetail and the Sliding Dovetail.
The crown jewel of these is the Secret Mitred Dovetail. It combines the Dovetail joint’s strength and quality with the Mitre joint’s aesthetically pleasing form. Central to traditional Western furniture design is the desire to hide the mechanics of a piece and only reveal it’s beauty. Much like a magician’s trick, this joint achieves the effect.
Although this collection of techniques have expanded and evolved over time, many incredibly complex joints, such as the Dovetail joint, can be seen in early Indian and Egyptian examples more than 5000-7000 years ago.
The art of furniture design, and the impeccable skill behind it’s making, is an ancient pursuit, and one which the illumination of history only enhances. Joinery is the artform by which we are able to see this skill and beauty. Like all great art forms, it only gets better with age.