There are a lot of different types of wood joints. The type of joint you use depends on the specific needs of your project.
Some joints rely on external sources of strength, like screws or splines. Others rely on the internal strength of the wood itself.
Butt Joint
A butt joint is a corner-shaped join that is used to connect two pieces of wood. It is one of the simplest and easiest joints to make.
In its simplest form, a butt joint involves spreading glue on the end grain of one piece of stock and pressing it into the face grain of the adjoining board. Glue alone does not provide enough strength, so it is recommended that nails, screws or dowels are used to reinforce the joint.
The most common form of butt joint is to use a number of nails that are driven into the members before they are brought together. Using this technique is a good way to ensure that the joints are not pulled apart when the wood is exposed to moisture or humidity.
A butt joint can also be reinforced by screws or nails inserted at alternating angles. However, you should be careful to drill pilot holes first if you are using hardwood. Hardwoods are notoriously prone to splitting when fasteners are driven into their ends.
Dado Joint
A dado joint is a common type of wood joint used to connect two or more pieces of wood together. It involves cutting a series of slots in one piece of wood and mating it with another piece that has corresponding grooves.
This is the most common joint used for bookcases, cabinetry and other woodworking projects. It is also a strong and simple way to join wood parts.
The dado is a rectangular groove cut across the width of a board that accepts another piece of wood. It provides a strong bond between the two and can be reinforced with glue.
The dado can be made with a handheld power tool like a router or with a traditional power saw. The most common type of dado is the through dado that cuts from edge to edge of the work-piece, but there are stopped and blind dadoes as well.
Dowel Joint
The Dowel Joint is a fast and simple way to join two pieces of wood together. This type of joint is strong and has the advantage of being fastener-free.
They are often used to strengthen butt joints and to build shelves and furniture. Usually they are dipped into glue before being inserted into the wood which creates a tighter wood-to-wood contact.
In general, dowels are about one-third to half the thickness of the wood they are glued to. This increases the mechanical resistance to lateral stresses and ensures that the connection maintains its alignment when glued up.
Making a dowel joint is relatively easy but it can be difficult to get it to fit perfectly. This is because it requires precise markings on both parts of the joint.
Dovetail Joint
Dovetail joints are a type of wood joint that is used on furniture and other pieces of wooden construction. They are a popular choice for furniture makers as they give their products strength and durability without using any mechanical fasteners (although modern joints use adhesives to help keep the joint from separating over time).
A dovetail is formed by joining two pieces of wood together at a right angle with a series of pins and tails. These trapezoidal shaped tails and pins fit together much like a jigsaw puzzle, providing a lot of tensile strength between them.
There are many different types of dovetail joints available to woodworkers. Some are visible from all sides, while others can be hidden.
Through dovetails are the most common type and are used by most woodworkers when creating frames or boxes. Half-blind dovetails are less visible and can be a more decorative option. Secret dovetails are also popular and completely hide the joint on all outside surfaces.