Woodworking joints come in a variety of configurations that join together two pieces of wood Some joints involve carving channels into two different wood pieces so that they lock together, while others use fasteners like nails or screws to hold them in place
Because wood joints are essential to woodworking, many joint types have been used for centuries and even millennia Carpenters and craftsmen of ancient China and Egypt helped perfect joinery methods that contractors and woodworkers still use today.
Top Wood Joint Types
Any project made of wood, from the frame of a house to a small cabinet, will soon run into a challenge—how do you connect or join two pieces of wood to form a larger structure? Here is a look at different types of wood joints and when to use each type to get the best result for your project.
1. Butt Joint
A butt joint is the most basic type of wood joint. Two different wood pieces simply sit side by side, with the butt of one workpiece adjacent to the butt of another workpiece.
Unlike other wood joints, the two pieces are not shaped or carved to lock into each other, and mechanical fasteners are typically used to hold them together.
In construction projects, butt joints may be found around baseboards and window trims, and they are an easy option when speed of construction matters more than looks.
Tip: While the basic butt joint is a workhorse and not a show pony, countersinking nails or screws can make it more attractive.
2. Miter Joint
“Miter” is another word for an angled cut—and the saw that makes the cut. In the term “miter joint,” it refers to two 45-degree angled cuts where the pieces of wood adjoin to create a 90-degree angle.
While the most common miter joints are made of 45-degree angles, miter butt joints can be cut at any range of angles. For example, if you want to build an octagonal-shaped structure, then you would cut each miter to 22.5 degrees.
Miter joints are commonly used at the visible, outside corners of door, window, and picture frames. They are stronger than butt joints because there is a greater surface area where the two wood pieces meet, but they still require both glue and mechanical fasteners to stay in place.
Tip: Be prepared to make small adjustments to the angle of your miter because most cuts for door and window frames are not precisely 45 degrees due to slight variations in drywall or other construction materials.
3. Coped Joint
A coped joint is a variation on the miter joint that lays underneath the miter joint. It addresses the reality that the corners of many rooms do not in fact meet at 90-degree angles.
Beneath the exterior (visible) miter joint, the two pieces of wood that make up a coped joint are carved like puzzle pieces to form an irregular but custom fit.
4. Tongue-and-Groove Joint
These joints consist of a tongue, or a ridge, on one piece of wood and a groove, or channel, on the other. The tongue slides into the groove to create a strong joint.
These joints are commonly used for elements that lie flat on a surface, such as hardwood floors. Most contractors don’t have to worry about creating them as flooring materials typically arrive with the joints already cut, and the only challenge is sliding the elements together.
Tip: If you are cutting your own tongue-and-groove joint, the tongue should be one-third of the thickness of the wood. For example, if a board is ¾” thick, the tongue should be ¼”.
5. Mortise Joint
Mortise joints are also known as mortise-and-tenon joints. While they look like butt joints from the outside, a protruding element is carved into one piece (the tenon) which slides into a corresponding recess (the mortise) in the other piece.
With the increased gluing surface area where the two wood pieces are joined, it is a significantly stronger—and more elegant—alternative to a butt joint.
Tip: Always cut the mortise first. It is easier to trim the tenon to fit the mortise than it is to approach the task the other way around.
6. Half-Lap Joint
With a half-lap joint, the ends of the two adjoining pieces of wood are reduced to half their thickness at the point where they overlap. There are stronger joints, but a half-lap has an aesthetic appeal over butt joints because they maintain a uniform thickness with the rest of the structure.
Half-lap joints are commonly used in framing and also in furniture construction, due to their great advantage: the frame remains uniform in thickness while other joints often result in a greater (an inconsistent) thickness as compared to the rest of the structure.
Thin pieces of wood can be weakened significantly when they lose half of their thickness, so half-lap joints are best suited to thicker pieces of wood.
7. Dado Joint
The dado joint gets its name from the Italian word for a die or plinth. It resembles a groove—a trench cut into one piece of wood parallel to the grain that another piece of wood slides into. But unlike a groove, a dado runs perpendicular to the grain.
Dado joints are most commonly used in shelving systems like cabinets and bookshelves. The dado cut should go no deeper than 1/3 into the wood. If you are using a piece that is ¾” thick, keep the cut to ¼”.
8. Rabbet Joint
Another joint with an unusual name (in this case from a Middle French word meaning “to force down”), a rabbet joint is related to the dado joint and consists of an open-sided channel along the end of a piece of wood. It often matches a corresponding cut in the piece it is paired with to create a double rabbet joint.
Rabbet joints are an aesthetically appealing joint, though not especially strong and are therefore best used in constructing the back of cabinet cases and other jobs where great strength isn’t a requirement.
Because of its larger surface area, a double rabbet is the better choice if you need a more rigid joint.
9. Pocket-Hole Joint
Pocket-hole joints rely on fasteners, namely pocket-hole screws. They are effectively a butt joint with a small pocket-hole drilled into one of the pieces of wood. The two pieces are then attached with a self-tapping pocket-hole screw.
Pocket-hole joints are strong and easy to make. Their downside is that they are less visually appealing than other joints making them better for temporary uses, or places where the joint will not be visible.
Tip: The screws will hold better in face or edge grain, so avoid screwing into end grain.
10. Edge-to-Edge Butt Joint
An edge to edge butt joint is similar to a square-ended butt joint, except pieces of wood are laid side by side on the edge. This is typically done to make a panel of wood from multiple pieces.
This type of joint is not very strong and difficult to reinforce with metal fasteners.
If the two pieces of wood you are joining together are more than 12 inches long, it is typically necessary to instead use an edge to edge dowel joint or biscuit joint – which we cover in more detail later in this post.
Dowel frame joints can be a lot stronger than you might think. Many furniture builders use dowel frame joints for a variety of different applications – from chairs to dresser drawers and more.
Note that fluted or spiral cut dowels are best as this gives additional “grip” compared to smooth dowels. Most hardwood stores sell packages of pre-cut wood dowels specifically for wood joinery that you can use.
To make the dowel frame joint, drill two holes that match up with each other in 2 pieces of wood. Insert the dowels with some wood glue in one piece of wood, and then add glue and attach the second piece of wood so the dowels slide in the holes you drilled.
In most cases, two dowels per joint are sufficient. Be sure they are at least a minimum of ¼ inch from both edges of the rail. For longer pieces of wood, you may want to use 3 or 4 dowels.
The advantage to this method is it can be simpler to make than box joints or dovetail joints and doesn’t require any specialized tools – just a drill!
11. Edge-to-Edge Dowel Joint
An edge to edge dowel joint is constructed very much like a square ended dowel joint, except in this case you are joining two pieces of wood side by side instead of perpendicularly at a 90 degree angle.
Depending on the length of your project and desired strength, you can insert dowels every 6, 9 or 12 inches apart. The more dowels = more strength, so consider the application for what you are using the dowel joint for.
12. Biscuit Joints
Biscuit joints are similar to dowel joints, except instead of dowels one uses “biscuits” which are small, flat oval shaped pieces of wood.
Biscuit joints are not typically as strong as dowel joints, but most hardwood stores do carry the wood biscuits in stock. One disadvantage to making biscuit joints is they typically require a specific tool called a biscuit plate joiner.
To make biscuit joints, the plate joiner is used to create slots where the biscuits will fit inside. You then glue together the biscuits into the slots with the adjoining piece of wood.
13. Corner Bridle Joint
Similar to a mortise and tenor joint or tongue and groove joint, with a corner bridled joint you are creating a slot in one piece of wood and cutting the other piece of wood to fit into the slot.
Many people often opt to insert two dowels through the side of the joint after the glue has set to improve the strength of this joint.
14. Box Joints
Box joints are an easy method of joining together pieces of wood when making a box. They are squares and square grooves cut out alternately on two edges of wood so that when you fit them together the squares line up to make a clean edge.
They can often times be hand cut simply with a saw, although of course there are router accessories sold that can make cutting them an easier task.
15. Dovetail Joint
Dovetail joints are probably one of the strongest types of wood joints and they can also give a nice look on a finished edge. Dovetail joints are often seen in box construction and drawer construction.
Dovetails are similar to box joints, but the “tails” are cut at an angle to provide additional strength.
Dovetail joints can be cut by hand using a saw or you can use a router. Cutting dovetail joints on a router is much easier when you make use of dovetail joint jig and template. Most router manufacturers sell this as an accessory.
16. Half Blind Dovetail Joint
A half blind dovetail joint makes sense when you want to join together two pieces of wood for a box, but do not want the dovetails to be seen from both sides.
Half blind dovetails are made very much in the same way as regular dovetail joints, except they are only cut half way through the corner, leaving a clean edge on the outside of the wood. This is a popular choice for drawer makers.
17. Sliding Dovetail Joints
Sliding dovetail joints are another popular option with many uses. In this type of joint, rather than cutting individual dovetails, the entire length of one board is cut into the dovetail shape, while the other piece of wood has a long groove.
Once the cuts are made, it is as simple as applying a little bit of wood glue and sliding the pieces of wood into place. While it is certainly possible to cut a sliding dovetail by hand, these are made easily on a router with the proper attachments and accessories.
18. Finger Joint / Comb Joint
Finger joints are very similar to dovetail joints, but the edges are usually cut in a saw-blade or comb like pattern.
Finger joints can be very strong, but some people do not like to use them because the zig-zag comb pattern is not something they want seen on the outside of their project. Of course, sometimes the design of these joints can be beautiful and add character to a piece.
To make finger joints, it is usually best to use a specific finger / comb router bit in order to make sure the two edges will line up together. Once the pieces are cut, simply apply glue and allow to dry.
