A joint is where two pieces of wood meet and are fixed together. The joint you choose decides how strong a piece is, how it looks, and how long it takes to make. Some joints rely on glue and fasteners; others interlock so the wood itself carries the load.
This post covers the common woodworking joints, what each suits, how each is usually cut, and tips for gluing and for choosing joints when you make products to sell.
How Joints Hold
Two things make a joint strong:
- Glue surface. Wood glue holds well on long grain, where the faces and edges of boards meet. It holds poorly on end grain, which soaks up glue like a bundle of straws. Joints that bring long grain together, such as rabbets, laps and tenons, are stronger than joints that glue end grain to a face.
- Mechanical interlock. Joints such as dovetails and mortise and tenons lock the parts together, so the joint still holds even if the glue fails.
Wood also moves with changes in humidity, mostly across its width. Good joints allow for this movement rather than fighting it.
Common Woodworking Joints
Butt Joint
The simplest joint: the end of one piece meets the face or edge of another. Glued alone, a butt joint is weak because it relies on end grain. It is usually reinforced with screws, nails, dowels, biscuits or pocket screws. Butt joints are fast and common in shop furniture, cabinet carcasses and painted pieces.
Miter Joint
Two pieces cut at an angle, usually 45 degrees, meet so no end grain shows. Miters are used for picture frames, boxes and trim. Like a butt joint, a miter glues end grain to end grain, so it is often strengthened with splines, keys, biscuits or nails.
Rabbet Joint
A rabbet is a step cut along the edge or end of a board. Another piece fits into the step, giving more glue surface than a butt joint and helping to locate the parts. Rabbets are used for cabinet backs, box corners and drawer construction. They can be cut on a table saw, with a router and rabbet bit, or with a rabbet plane, and fitting a back into rabbets helps hold a cabinet or bookcase square.
Dado and Stopped Dado
A dado is a flat-bottomed groove cut across the grain, into which another board fits. It is the standard joint for shelves in bookcases and cabinets, because the groove supports the shelf along its full width. A stopped dado ends before the front edge, so the joint does not show from the front. Dados are cut with a dado blade on a table saw or a straight bit in a router.
Tongue and Dado (Dado and Rabbet)
One piece has a rabbet that forms a tongue, which fits into a dado in the other. It locates the parts well and looks neat. Because of how it is aligned with the grain, it is not one of the strongest joints, but it is more than strong enough for small boxes, small cupboard shelves and the backs of drawers.
Tongue and Groove
A tongue along the edge of one board fits a groove in the next. Used to join boards edge to edge in paneling, flooring and backs, it keeps the faces aligned and lets the boards move with humidity.
Half-Lap Joint
Each piece has half its thickness removed where they overlap, so they sit flush. Half-laps are quick to cut and give a large long-grain glue surface. They hide the end grain of each piece and look neat, which makes them a good choice for frames of all kinds, as well as cross pieces and simple tables.
Splice Joints
Splice joints join two pieces end to end to make a longer piece. The four main types are the half-lap splice, the bevel lap splice, the tabled splice and the tapered finger splice. Splices are used where a board is not long enough, in timber framing, and in repairs.
Squared (half-lap) splice. Each end has half its thickness removed for a set length, and the two overlap. It is simple and gives a good glue surface, and is usually reinforced with fasteners.
Bevel lap splice. Similar to the half-lap splice, but the overlapping faces are cut at an angle. It is stronger than a half-lap splice, but still needs glue and fasteners.
Mortise and Tenon
A tenon, a tongue on the end of one piece, fits into a mortise, a matching slot in the other. It is one of the oldest and strongest woodworking joints, with a large long-grain glue surface and a mechanical fit that resists racking. It is the standard joint for tables, chairs, doors and frames that take heavy loads. Mortises are cut with a chisel, a hollow-chisel mortiser, a router or a drill and chisel; tenons are cut with a saw, a table saw or a router. Loose-tenon systems use a separate tenon glued into mortises in both pieces. The joint is not decorative, but it lasts.
A well-fitted tenon slides in with hand pressure. If you need to hammer it in when dry, it will be too tight once glue makes the wood swell. Trim it with a shoulder plane or chisel.
Dovetail Joint
Fan-shaped tails on one piece interlock with pins on the other. The shape resists being pulled apart in one direction, which is why dovetails are the classic joint for drawer fronts and box corners. They are also valued for their looks, and visible dovetails are a mark of careful handwork.
- Through dovetails show on both faces.
- Half-blind dovetails show on one face only, because the pins are cut shorter so they do not pass through the mating piece. They are used on drawer fronts, so the joint is hidden from the front.
Dovetails can be cut by hand with a dovetail saw and chisels, or with a router and a dovetail jig.
Box (Finger) Joint
Square fingers on each piece interlock at a corner. Box joints have a large glue surface and are strong, and they are quicker to cut than dovetails with a jig on a table saw or router table. They suit boxes, drawers and crates.
Bridle Joint
A variation of the mortise and tenon in which the mortise is open on the end, like a slot. Easy to cut on a table saw or band saw, it is used for frames and table bases.
Joints Made With Jigs and Fasteners
- Pocket screws: angled screws driven through a hole drilled with a pocket hole jig. Fast and strong enough for cabinets, face frames and many furniture parts.
- Dowels: wooden pins glued into matching holes in both pieces, aligned with a doweling jig.
- Biscuits: flat, oval wafers glued into slots cut with a biscuit joiner. They mainly align edge joints and panels and add some strength.
- Splines and keys: thin strips glued into slots across a joint, often in miters, which add strength and can be a decorative feature.
See woodworking tools for beginners for joinery jigs.
Gluing Tips
- Dry fit first. Assemble every joint without glue to check the fit and plan the clamping. If you have to use more than light tapping with a mallet, the joint is too tight.
- Assemble each joint fully. Do not push several joints partly together and then try to close them all. A partly assembled joint can lock up as the glue grabs, and may not come apart without damage.
- Fix loose joints properly. Glue a thin piece of wood to a loose tenon and trim it to fit. Gap-filling epoxy can help where a joint is slightly loose, but it does not replace a good fit.
- Use enough clamps, with even pressure, and check the piece is square before the glue sets.
Keep Glue Off the Surface
Glue that squeezes out of a joint can be hard to remove and can spoil a stain or finish. One way to avoid it:
- Clamp the two pieces together dry.
- Run masking tape along the joint line.
- Cut the tape along the joint line with a sharp knife.
- Separate the pieces. Each now has tape running right to the edge of the joint.
- Apply glue and clamp as usual. Squeeze-out lands on the tape.
- Peel off the tape before the glue fully hardens, and the excess comes away with it.
Choosing Joints for Products You Sell
- Match the joint to the load. Chairs, tables and beds need strong joints such as mortise and tenons. Boxes, frames and small shelves can use simpler joints.
- Match the joint to the look. Visible dovetails, box joints and keyed miters can be a selling feature. Hidden joints suit painted or simple pieces.
- Match the joint to the price. Hand-cut joinery takes time, and buyers who value it will pay for it. For lower-priced items made in batches, pocket screws, dowels and jig-cut joints keep the cost down.
- Be consistent. Use jigs and templates so joints are the same on every piece in a batch.
- Describe the joinery in your listings. “Hand-cut dovetails” or “mortise and tenon construction” tells buyers what they are paying for.
For more on making and selling, see how to create wood projects that sell.
For jigs that cut joints the same way on every piece, see woodworking jigs and batch production.
Practical Tips
- Learn a few joints well before trying many.
- Practise each joint on scrap before using it on a project.
- Dry fit every joint before gluing.
- Choose long-grain glue joints where strength matters.
- Use jigs for repeated joints in batch work.
For the hand tools used to cut and fit joints, see woodworking hand tool basics.
