Woodworking joints are essential tools to join two pieces of wood together. There are more than a dozen woodworking joints, and each type functions differently. Although some may have similarities in their work, each has its uniqueness. It pays to know the types of wood joints for specific projects to achieve high-quality artistry.
The primary purpose of joints is to offer flexibility, durability, aesthetic appeal, and strength to your woodworking project. These wood joints use specific tools and equipment to cut the joints and bind them using bindings, adhesives (glue), and fasteners (nails, screws). Please find the most popular wood joints and learn their uses. Keep reading.
What is Wood Joint?
Before we go to the different types of wood joints, let’s discuss what wood joints are. A woodworking joint is the part of your workpiece where you combine two pieces of wood or plank to create a sturdy supporting construction. Woodworkers could create joints between the face and end or edges of the workpiece in various directions.
What about woodworking joinery? It refers to the craft or art of securing, joining or connecting individual wooden construction pieces using a particular cut (rabbet, dovetail, etc.) on the sides or ends of the wood pieces. It could be at the right angle, at an angle, or in the length’s direction.
Some wood joints use fasteners or glues to strengthen and reinforce them. The construction of wood pieces seems weak if you do not make the joints carefully. Tall bookcases, cabinets, and heavy furniture should have a sturdy wood joint, or they will fall or crash due to heavy loads.
Woodworking joints come in various types; some are easy to make, and some are complex. It needs practice and patience to master the craft. Certain wood joints require hand tools, but the job is slower and more precise if you use a power tool or machine. Brace yourself with our list of woodworking joints and their uses.
Here they are:
Wood Joint Types and their Uses
1) Butt Joint
Butt joints are one of the most accessible woodworking joints by joining two wood pieces at a right angle. Woodworkers butt the workpiece together to form a corner. They use mechanical fasteners to reinforce the joints.
You have to strengthen the joinery as butt joints are one of the weakest wood joints. Blame it on the workpiece orientation, where it produces an end grain-to-long grain surface gluing.
Using an adhesive is not a guarantee that it can provide lateral strength to the woodworking project. Even a slight poking with your bare hands can break the joints, so think twice if you will use it in your next project.
2) Biscuit Joint
Biscuit joints are a modified version of the butt joint to reinforce the wood construction. Woodworkers apply the tongue and groove technique to create a strong joint. The biscuit consists of compressed and dried wood-like beech and has an oval shape.
They install the biscuit in uniform mortises of joint wood pieces. A biscuit joiner can help create the mortises, never mind about the accuracy of the mortises. The biscuit joiner offers gluing flexibility.
To succeed in your project, you must get the accurate distance from both joint pieces to find the mortise. Biscuit joints need to provide precise alignment, and it is time-consuming to cut the mortise for each wood piece, not to mention the cost of plate joiner or biscuit joiner.
A similar method that is less cumbersome is the dowel joint, where you do not make a slot cut but drill some holes in the timber’s ends with wooden pins around the glue blocks. The biscuit joint is ideal for wooden counters and tabletops.
3) Bridle Joint
This woodworking joint works similarly to a tenon and mortise. Sometimes it is called a tongue & force joint. It is not ideal for beginners as creating is cumbersome. Woodworkers cut a tenon on a workpiece’s end and a mortise into the other workpiece’s end to receive it. The bridle joint offers support to the workpiece’ notched end.
Another option is to cut the mortise and tenon to full width right on the tenon workpiece, thus creating three surfaces for gluing. A corner comes out after joining the ends of two workpieces using a corner bridle joint. This method offers reinforcement in compression and prevents racking. It would be best if you had a pin or fastener to strengthen the joint.
Once you have shaped the frame, you must use the corner bridles to connect the frame pieces. The joint integrity remains unfazed even if you decide to remove the material from the assembled parts.
T-bridle works similarly to a bridle joint, where you join the end of a workpiece to the center of another wood piece. Bridle joints are excellent for rails, rafters, and sloped beams.
4) Dado Joint
Dado joints comprise three sides when you see its cross-section. Although they look like grooves, they differ in the cut’s direction. Woodworkers cut several dadoes or slots perpendicularly on the wood piece surface grain.
Dado joints are ideal for shelving bookcases or cabinets or connecting wood parts. Groove cut works the opposite way by cutting a dado parallel to the grain of another wood piece that slides into it. A through dado cuts through the wood surface with an opening at the ends, while a stopped dado has one or both ends halt before it meets the surface edge.
5) Dovetail Joint
Dovetail works best for your project if you want a sturdy woodworking joint. It offers tensile strength to a corner or side of a drawer, shelves of cabinets, and framing.
A dovetail joint is perfect for joining the drawer’s sides to the front. Its interlocking joinery consists of pins, and tails cut into another board’s end. These trapezoidal pins and tails offer a durable edge to the furniture.
In yesteryears, woodworkers cover the pins and tails with veneer to hide them, but in modern woodworking, its presence signifies fine craftsmanship. Dovetail joints become a permanent construction once you have applied an adhesive to them, which means mechanical fasteners are no longer needed.
Before cutting a dovetail joint, scribble the baselines with a sharp gauge as your guide to get an accurate cut.
6) Finger Joint
Finger joints are a popular wood joinery method because they are easy to use. Sometimes confused as a box joint, the finger joint connects two wood pieces at their proper angles to create a longboard. It works similarly with dovetail, but they use square pins, and dovetail uses angled pins. Dovetails have mechanical strength, making them resilient against pressure.
To make a finger joint, you must use a wood router with a jig, or a table saw. Start by cutting fingers like the box joint, but it should be more profound. In creating a box joint, two wood pieces should be at ninety degrees to get a compact corner. In finger joints, place the matching wood pieces flat on the surface, then use a thin layer of glue between the fingers to assemble the joints.
7) Lap Joint
A lap joint requires you to place a workpiece on top of another wood piece to create an irregular pattern on the ends of the wood parts. The resulting design could be half lap, dovetail lap, or cross-lap pattern.
This wood joint offers robust joinery due to its wide connection surface. It would be best if you had glue to keep the joints strong, ensuring that the long edges lay flat. Aside from adhesive, you can use mechanical fasteners, such as nails and screws.
You can cut lap joints at the ends or center of the wood. A lap joint is popular in building cottages or log cabins in the olden days. They are excellent for making toys, chairs, and tables.
8) Half Lap Joint
Like the lap joint, the half lap joint is also popular in woodworking. To create a lap joint, you must remove the material from the wood pieces to achieve a uniform thickness of the resulting joint of wood piece.
In short, you will create the same thickness of all the wood pieces by removing half of the thickness of each wood piece. This method will result in a substantial and flawless connection.
The term half lap is a derivative of the word full lap joint. It means laying a wood piece on top of another and pinning them with mechanical fasteners.
Woodworkers use half-lap joints to build workshop storage items or join two boards for a flat surface. They prefer using half-laps than full-lap joints because they are easy to create and offer high tensile strength through the long grain to long grain surface for gluing.
It is resilient against racking with its sturdy shoulders. You can strengthen the joint using mechanical fasteners or dowels to avoid diagonal distortion.
9) Mortise & Tenon Joints
Mortise and tenon joints are one of the most popular woodworking joints because it is robust and straightforward. Its name derives from mortise and tenon. Woodworkers use two pieces of wood to connect them at ninety degrees and then insert the end of one wood piece to hold another wood piece.
The first wood piece’s end is known as a tenon, while the second wood piece’s end is called a mortise. If you want perfect wood construction, you must be careful in cutting the mortise and tenon joints, especially when building fine furniture and heirloom pieces. Wood glue will make the joint permanent or pin a mechanical fastener.
When we say mortise, it refers to a cavity that you cut into a wood piece where it receives the tenon. A tenon is the projection of a wood piece’s end where it inserts into the mortise. You can tell the difference between a mortise and a tenon quickly. A tenon is taller but not wide enough. The ideal tenon size is one-third of the wood piece thickness.
10) Pocket Hole Joint
Pocket hole joints are popular wood joints due to their simplicity. It involves a butt joint with a pocket hole for screws. It requires you to create two drillings for the pocket holes by counterboring the pocket hole, where it takes the screw head in the wood piece.
Drill the second hole, known as the pilot hole, with the same center line as the pocket hole. It is in the pocket hole where the screw passes through a wood piece and into the adjacent wood piece.
To achieve an accurate pocket hole joint, you must use two different sizes of drill bits. Woodworkers use a Kreg Jig to drill pocket holes with precise depth and angle. Reinforce the joint by using glue.
A Kreg Jig can be more expensive than a DIY mortise, and tenon jigs are more robust than a store-bought jig. Pocket hole joints are popular in making cabinet doors, door jambs, residential archways, and face frames.
11) Rabbet Joint
A rabbet joint has two sides with a concave surface end. It is a product of cutting a recess into the wood piece edge. The protruding edge resembles a tongue and groove joint but does not have two side cuts.
Rabbet joints are less complex but more robust compared to butt joints. It is ideal for supporting the back edge of cabinets, allowing the back edge to fit seamlessly with the sides. It is perfect for inserting a glass pane around the frame’s edge. Doors and windowsills use this technique to hold when inserting the glass in a frame.
12) Tongue & Groove Joint
Also known as edge-to-edge joint, tongue & groove joint is a popular choice in woodworking. All you have to do is to connect two flat workpieces to make a larger panel. It leads to creating a board with a long edge at the edge. The other edge consists of a groove cut that receives the wood extension.
Secure the joints by gluing or pinning mechanical fasteners, especially in furniture making, parquetry, paneling, or flooring applications. It is also ideal for creating square joints, where you cut the groove into the board’s surface while milling the tongue on the side.
This wood joint has two distinguishing characteristics: a groove or slot along one edge of the wood piece and a tongue on the mating edge of another wood piece. These two pieces of wood fit closer together.
13) Mitered Butt/Miter Joint
This wood joinery connects two workpieces at a corner, where a line bisects at the correct angle. Woodworkers cut the workpiece at 45 degrees and then join them together to produce a ninety-degree angle. A miter saw runs this joint connection smoothly.
This joinery has a strong corner with an appealing look, as the joints do not appear at the end grain. It is better than butt joints if you work on corners of your projects. Miter joints also cut on angles lesser or greater than ninety degrees.
These wood joints are suitable for molding, trimming, MDF structures, kitchen cabinets, and picture frames. If you want to secure the joints firmly, use adhesive or mechanical fasteners.
14) Dowel Joint
Dowel joints are less popular wood joinery because it is complex to make. This type of joinery connects two wood pieces by drilling holes in the spot where the two wood pieces meet. It used to be popular before, but with so many woodworking joineries available today, carpenters prefer to use something other than them.
Dowel joints work similarly to pocket hole joints but appeal to your eyes. Each piece of wood has a dowel hole where you apply a thin layer of glue and insert the dowels or wooden pegs to connect them. The wooden pegs reinforce strength compared to mechanical fasteners. These wooden pegs strengthen the two wood pieces to stay connected.
Don’t you know that expandable fluted pegs increase their size by 1/32 inches once they come into contact with the glue’s moisture? This chemical reaction helps hold the joints firmly. You can also use metal screws if wooden pegs are unavailable. Pegs look attractive but are less robust than metal screws.
15) Box Joint
Box joints join two wood pieces at a corner by connecting their ends with teeth to interlock them. It works similarly with a dovetail joint, but they have square pins.
They are more robust compared to butt joints due to their interlocking design.
This wood joinery offers a wide glue surface for seamless and solid corner joints. Use a router or table saw with dado blades to carve out symmetrical slots to create the fingers, which are rectangular projections of the joints.
The fingers become permanent once you glue the joints and insert the fingers. Box joinery is easy to make and works on wood types and plywood. Carcasses, wooden boxes, and odd-shaped boxes use box joinery.
16) Birdsmouth Joint
Also known as bird’s beak cut or bird’s beak joint, the birdsmouth joinery forms a triangular groove or notch cut into a wood rafter. It can lie at an accurate angle over a supporting wall, stud, or timber.
This joinery reinforces an unstable stud, which has a flat top. If you allow a flat stud by taking another wood or rafter to set at an angle against the stud’s top, there is no strong support, as the two boards will only touch each other along a single top edge.
Cutting the accurate notch on the construction allows the two boards to fit together instead of merely contacting. There is a broader surface area for contact, ensuring that the rafter is tightly secure at the right angle. In short, a birdsmouth joinery is a wood joint that joins your roof’s rafter to the supporting wall’s top plate.
17) Splice Joint
A splice joint is one of the old-fashioned woodworking joineries. Carpenters use them when they need to extend the timber’s length, especially if longer woods are unavailable.
Splice joints come in various designs, but their primary purpose is to connect two workpieces from end to end. Since gluing the wood ends together is not strong enough due to the grain’s orientation and the surface is small, this joinery is weak. It is a better option than the scarf joint and butt joint.
To counter this issue, you must create a parallel gluing surface as the primary structural bond. Use a hand saw to carve out the splice joints and glue the surface for reinforcement.
18) Coped Joint
The coped joint comprises a single side square cut with the remaining cuts in the corner. It is a modified version of the miter joint, which lies beneath the miter joint. It is popular in making larger molding patterns and ornate designs in room corners that are not square.
This joinery has many downsides, even if you are cautious in measuring and cutting the joints since the corners of a room are not usually square or not at a ninety-degree angle. Use a good-quality coping saw with a sharp blade. Adjust the frame tightly to create seamless and accurate coped joints.
Summary
Woodworking success lies in making the proper woodworking joinery for a specific project. There are many things to consider before you begin cutting the joints. Consider the design, wood type, preparation, finishing, and durability of your wood construction. Our wood joints list can help you better understand the type suitable for your project.