Understanding wood joints is the foundation of all woodworking. Before you can build a table, a shelf, a box, or a cabinet, you need to know how pieces of wood connect to each other — and which connection is right for each situation.
The good news: you only need to know five joints to cover 95% of all DIY woodworking projects. Here they are, from simplest to most advanced.
Joint 1 — The Butt Joint
What it is
The simplest joint of all: one piece of wood butted squarely against another and fastened with screws, nails, or glue. No cutting required beyond straight, square ends.
When to use it
Anywhere appearance isn't critical — the inside of boxes, rough framing, carcass backs, simple shelving. It's fast and requires no special tools but it's the weakest joint mechanically because wood glue on end grain absorbs poorly.
How to make it stronger
Add screws or nails alongside the glue. For extra strength, add a small glue block inside the corner — a scrap piece glued and screwed into both faces. Pocket hole screws (made with a pocket hole jig) are the modern upgrade to a basic butt joint and give surprisingly strong results.
💡 Key Rule: Always pre-drill pilot holes before driving screws into end grain — end grain splits very easily without a pilot hole.
Joint 2 — The Lap Joint
What it is
Half the thickness is removed from each piece so they overlap and sit flush. The result is a flat, flush joint that's significantly stronger than a butt joint because you're now gluing face grain to face grain.
When to use it
Frames, crosses, grids, and any place where two pieces need to cross each other at the same level. Picture frames, garden trellises, and workbench bases all commonly use lap joints.
How to cut it
Mark half the thickness and the width of the overlapping piece. Make multiple saw cuts within the waste area down to your depth line, then chisel out the waste. Clean up the bottom of the recess with a sharp chisel held flat. Test fit — the pieces should slot together with hand pressure and sit perfectly flush.
Joint 3 — The Dado Joint
What it is
A rectangular channel cut across the grain of one board that another board slides into. Think of how a shelf sits inside a bookcase — that slot is a dado.
When to use it
Shelves in bookcases, drawer bottoms, cabinet dividers — anywhere a board needs to slot into another at a right angle. It's one of the strongest and most common joints in furniture making.
How to cut it by hand
Mark the width and depth of the channel. Make two saw cuts to define the edges, then make several more saw cuts within the waste. Use a chisel to break out the waste in layers, working from both sides toward the center. A router makes this faster but a chisel and saw work perfectly — just take your time paring the bottom flat.
Joint 4 — The Mortise & Tenon
What it is
A rectangular peg (tenon) cut on one piece that fits into a matching rectangular hole (mortise) in another. This is one of the oldest and strongest wood joints ever devised — used in furniture for thousands of years.
When to use it
Chair legs, table aprons, door frames, bed rails — anywhere you need a strong, permanent right-angle joint that will resist racking forces. A well-made mortise and tenon is stronger than the wood itself.
How to cut it
The tenon is cut with a saw — two cheek cuts and two shoulder cuts. The mortise is made by drilling out most of the waste with a drill and cleaning up the walls and corners with a sharp chisel. The fit should be snug but not forced — you should be able to push it together with hand pressure. Glue both surfaces when assembling and it will never come apart.
💡 Rule of Thirds: The tenon should be one third the thickness of the piece it's cut from. So on a 1.5" thick board, your tenon is ½" thick. This gives the best balance of strength in both pieces.
Joint 5 — The Dovetail Joint
What it is
Interlocking fan-shaped tails and narrow pins that mesh together. The angled shape makes it mechanically impossible to pull apart along the grain — it only comes apart the way it went together. It's as beautiful as it is functional.
When to use it
Drawer construction, box corners, fine furniture carcase work — anywhere you want maximum strength at a corner joint AND want the joinery itself to be a visual feature. Exposed dovetails are the sign of quality craftsmanship.
How to cut it
Cut the tails first using a dovetail saw — thin-kerf, fine-tooth, angled. Chop the waste between tails with a sharp chisel. Then trace the tails onto your pin board using a marking knife, cut the pins, and chop out the waste. The fit should be snug. We have a full detailed tutorial in our Dovetail Toolbox project if you want to practice these cuts on a real project right away.
Which Joint Should I Use?
🔧 Quick Reference
- Butt joint — Fast builds, hidden areas, rough work
- Lap joint — Frames, crosses, grids — flat results
- Dado joint — Shelves, cabinets, drawer bottoms
- Mortise & tenon — Chairs, tables, frames — maximum strength
- Dovetail — Drawers, boxes — beauty + strength