Joints

How pieces of wood meet: dovetail, mortise and tenon, mitre, and the rest.

• Butt jointThe simplest joint in woodworking: one piece's end or side placed flush against the other, meeting square with nothing cut to lock them together.
• Mitre jointTwo pieces cut at an angle, most often forty five degrees as in a picture frame or skirting, though a plain mitre is weak on its own.
• Dovetail jointTwo boards locked at a corner by a row of angled, wedge-shaped pins fitted into matching sockets, resisting pulling loads better than most joints.
• Mortise and tenon jointTwo pieces locked by a tongue, the tenon, pushed into a matching slot, the mortise, cut into the other, usually glued and sometimes pegged.
• Housing jointA slot cut across the grain of one piece so another piece's end or edge drops into it square, the ordinary way to fit a shelf into a cupboard.
• Lap jointTwo pieces of wood overlapped with a recess cut in one or both so their broad faces can meet for glue or fixing.
• Rebate jointA step-shaped recess cut along the edge or end of a piece of wood, leaving a shoulder and matching face for another piece to fit against.
• Dowel jointTwo pieces held together with short round wooden pegs glued tightly into matching bored holes so the faces line up and cannot slide or twist.
• Tongue and groove jointTwo boards joined edge to edge by a ridge on one, the tongue, locking into a matching channel, the groove, on the other so the faces stay flush.
• Halving jointTwo timbers each notched away by half their thickness so they overlap and sit flush where they cross, a common beginner's exercise.
• Scarf jointAn end joint, also called a splice, connecting two timbers end to end along their length so together they act as one piece longer than either alone.
• Notched jointA piece removed from one timber so a second timber crossing it sits flush against it, the notch sized to match the second timber's thickness.
• Bridle jointA mortise and tenon worked in reverse, with one piece cut away in the middle to straddle a projecting tongue standing on the other.
• Edge jointTwo boards joined along their edges, usually with glue alone, to make a single wider board or panel, strong because the grain runs long to long.
• Biscuit jointTwo mating pieces held together with a compressed-wood oval plate, called a biscuit, glued into slots cut into both pieces where they meet.
• Finger jointAlso called a box or comb joint: boards joined at a corner by straight interlocking rectangular fingers, glued along many tight grain lines.
• Cogged jointTwo timbers connected by cutting a projecting tooth, or cog, on one and a matching slot in the other so they partly sink into each other.
• Knuckle jointA furniture joint allowing a part such as a table's swing leg to move, needing careful fitting and easy to confuse with joints of the same name.
• Housed dovetailA housing joint whose groove is cut in a dovetail shape rather than square, called ari-dome in Japanese joinery, used in drawers and carcase work.
• Handrail bolt jointA double-ended screw fitted with a nut at each end, drawing two adjoining pieces of timber together to hold a handrail joint closed.
• Hammer-headed keyA hardwood peg with a hammer-shaped head at each end, driven into a curved handrail joint alongside tongues to hold the pieces together.
• Dovetail keyA hardwood insert fitted into matching recesses across a joint to reinforce the adjoining wood and hold it together.
• Tenon and fox wedgeA tenon secured by a fox wedge, a wedge driven into a cut made in the tenon itself to spread and lock it inside its mortise.
• Domino jointPieces joined with a loose tenon, a separate domino-shaped piece fitted into matching mortises cut in both pieces.
• Coopered jointSeveral boards with bevelled edges glued into a curved arc rather than a flat panel, planed smooth until it reads as one continuous curve.
• Birdsmouth jointA roof-framing joint in which a rafter has a notch that seats it onto the horizontal wall plate at the top of a wall.
• Halved and mitred jointA joint combining a halving, made by removing matching half-depth sections, with a mitre, whose ends meet at matching angles.