The main ways to join two boards at a corner are the butt joint (with screws, pocket screws, dowels or biscuits), the rabbet, the miter (plain, splined or lock miter), the box joint, the dovetail, the half-lap, the bridle and the mortise and tenon. Which one to use depends on whether you are building a box or a frame, how strong the corner must be, whether the joint will show, and the tools you have.
Corner joints split into two families. Box and carcass corners join two wide boards edge to edge, as in a chest, drawer or cabinet. Frame corners join two narrow pieces, as in a door, a picture frame or a table base. A joint that is excellent for one is often awkward for the other. For every type of joint, not only corners, see our guide to 18 wood joinery techniques.
Wood corner joints compared
| Joint | Strength | Tools | Best for |
|---|---|---|---|
| Butt joint | Weak alone (end grain); fine with screws, nails or reinforcement | Any saw | Shop furniture, quick boxes, carcasses that will be fastened |
| Pocket screw butt joint | Good for face frames and cabinets | Pocket hole jig | Face frames, cabinet boxes, desks |
| Dowel joint | Good | Doweling jig, drill | Cabinets, chairs, flat-pack style joints |
| Biscuit joint | Moderate: mainly alignment | Biscuit joiner | Casework, panels, quick alignment |
| Rabbet joint | Better than a butt: more glue area, locates the parts | Table saw or router | Cabinet backs, drawer sides, boxes |
| Locking rabbet | Strong | Table saw or router table | Drawers |
| Miter joint | Weak alone (end grain to end grain) | Miter saw or sled | Picture frames, trim, boxes where looks matter |
| Splined or keyed miter | Strong; keys are decorative too | Table saw and jig | Boxes, frames |
| Lock miter | Strong and self-aligning | Router table, lock miter bit | Columns, hollow legs, boxes |
| Box (finger) joint | Very strong: large long-grain glue area | Table saw or router jig | Boxes, drawers, toy chests |
| Through dovetail | Very strong, mechanical lock | Hand saw and chisels, or a jig | Chests, carcasses, drawer backs |
| Half-blind dovetail | Very strong | Hand tools or dovetail jig | Drawer fronts |
| Corner half-lap | Good with glue | Table saw, router or hand saw | Frames, workbench parts, simple doors |
| Corner bridle joint | Strong | Table saw or band saw | Frames, table bases, doors |
| Mortise and tenon | Very strong for frames | Chisels, mortiser or router | Tables, chairs, doors, beds |
Box and carcass corners
Butt joint
One board’s end against the other’s face, glued and fastened. It is the fastest corner to make, but glue alone holds poorly because one face is end grain. Use it where screws, nails or a back panel do the holding.
Pocket screw butt joint
A butt joint pulled tight with screws driven at an angle from the inside. The screws clamp the joint while the glue sets, so no clamps are needed. The holes go on the inside or back face where they will not be seen.
Dowel joint
A butt joint with glued dowels across it for alignment and strength. Two or more dowels per joint keep the faces flush and add long-grain glue surface inside the joint. A doweling jig keeps the holes lined up.
Biscuit joint
Oval beech biscuits glued into matching slots. Biscuits swell with the glue and lock in. They are quick and forgiving, but they add less strength than dowels or a rabbet.
Rabbet joint
One board sits in an L-shaped step cut along the end of the other. The step locates the parts so the box goes together square, and it doubles the glue area of a butt joint. Usually reinforced with pins or screws.
Locking rabbet
A rabbet with a tongue that hooks into a dado, so it resists pulling apart. Cut entirely on the table saw, it is a fast and strong drawer joint that hides most of the end grain from the front.
Miter joint
Both pieces cut at 45° so no end grain shows. It looks clean because no end grain shows, but end-grain-to-end-grain glue is weak, so most miters need splines, keys, biscuits or nails. The miter angle calculator gives the saw setting for any number of sides, including compound angles.
Splined or keyed miter
A miter with a thin spline or contrasting keys glued across the joint. The spline runs across the joint line and adds long-grain glue area. Keys in a contrasting wood turn the reinforcement into decoration.
Lock miter
A miter with interlocking profiles cut by a special router bit. One bit cuts both pieces, and the profiles interlock so the joint closes square. Setting up the bit takes care; once set, it repeats perfectly.
Box (finger) joint
Square interlocking fingers on both boards. All those fingers give a huge long-grain glue area, so a well-fitted box joint is as strong as a dovetail in most uses. A simple sled on the table saw cuts them.
Through dovetail
Flared tails and pins that lock in one direction and show on both faces. The flare of the tails means the joint cannot pull apart in one direction even without glue. Lay out the tails and pins for any board width with the dovetail layout calculator.
Half-blind dovetail
Dovetails that show on one face only. The front stays clean, which is why drawer fronts use it. It is harder to cut by hand than a through dovetail; router jigs make it routine.
Frame corners
Corner half-lap
Half the thickness removed from each piece so they overlap flush. Each piece loses half its thickness where they overlap, and the large flat glue faces make a solid corner for simple frames and workshop projects.
Corner bridle joint
An open slot on one piece and a matching tongue on the other. Like an open mortise and tenon. It is easy to cut accurately on the table saw with a tenoning jig and is stronger than a half-lap.
Mortise and tenon
A tenon on the rail glued into a mortise cut in the leg or stile. The standard frame joint for furniture. A tenon about a third of the stock thickness is the usual starting point; the mortise and tenon calculator works out the tenon thickness, width and length and the mortise depth.
How to choose a corner joint
- Box or frame? Wide boards meeting: rabbets, box joints, dovetails, miters. Narrow pieces meeting: half-laps, bridles, mortise and tenon.
- Will it show? If the corner is on display, a miter hides the end grain, and a box joint or through dovetail turns the joint into a feature.
- How much load? Chairs, tables and anything that racks need a frame joint with a lot of glue area. A cabinet with a glued-in back can use simpler corners, because the back keeps it square.
- What tools do you have? A drill and a pocket-hole or dowel jig cover most beginner projects. A table saw adds rabbets, box joints, splines and bridles. Hand saws and chisels cut any of them, given time.
- How many? For one box, cut joints by hand. For a dozen drawers, set up a jig once.
Gluing corner joints
Long-grain to long-grain glue faces are what make a corner strong; end grain adds little. Spread glue thinly on both faces, clamp until the joint closes without starving it, and check the corner is square by measuring the diagonals. The wood glue coverage calculator works out how much glue a glue-up needs.
Frequently asked questions
What is the strongest wood corner joint?
For boxes and casework, a through dovetail or a box (finger) joint: both lock mechanically and have a large long-grain glue area. For frames, a mortise and tenon or a bridle joint.
What is the easiest corner joint for a beginner?
A butt joint reinforced with screws, pocket screws or dowels. A rabbet joint is the next step up and needs only one cut on a table saw or router.
How do you join two pieces of wood at 90 degrees without screws?
Use a joint that holds by glue and shape: a rabbet, a miter with splines, a box joint, a dovetail, a half-lap or a bridle joint. All of them can be glued and clamped with no metal fasteners.
Why are glued butt joints weak?
One of the two glue faces is end grain, which soaks up glue and bonds poorly. Adding dowels, biscuits, splines or screws, or switching to a joint with long-grain glue faces, fixes that.
What corner joint is used for drawers?
Traditionally half-blind dovetails at the front and through dovetails at the back. Locking rabbets and box joints are common faster alternatives.