Joinery is simply how two pieces of wood are held together. Beginners often reach for screws and glue alone, which works for some projects but ignores how wood moves and where loads fall. Three traditional joints cover the large majority of early work, each suited to a different job.

1. The butt joint

The simplest joint: two squared ends or faces brought together and fastened. It relies entirely on glue, fasteners or reinforcement, because there is no interlocking geometry. It is fast and honest for boxes, frames and rough carcasses where appearance and long-term load are modest.

Where it fails: end-grain to long-grain glue surfaces are weak. If a butt joint will carry stress, reinforce it with dowels, splines or a mechanical fastener rather than trusting glue alone.

2. The mortise-and-tenon

A projecting tongue, the tenon, fits into a matching cavity, the mortise. This is the backbone of frame-and-panel work, chairs, tables and doors. The interlocking surfaces give the joint mechanical strength and a large long-grain gluing area, which is what makes it durable.

Diagram of a mortise-and-tenon joint
Mortise-and-tenon geometry. Source: Wikimedia Commons (CC BY-SA 3.0).

Cutting order that helps beginners

  1. Mark the mortise first and cut it to depth.
  2. Size the tenon to the finished mortise, not to a number.
  3. Test the fit dry; it should slide with hand pressure, not hammer blows.

3. The dovetail

Interlocking wedge-shaped pins and tails resist being pulled apart in one direction, which makes the dovetail the classic choice for drawer fronts and box corners. It is the most demanding of the three to cut by hand, and also the most rewarding to learn because it trains sawing to a line.

JointStrengthDifficultyTypical use
ButtLow without reinforcementEasySimple boxes, rough frames
Mortise-and-tenonHighModerateTables, chairs, doors
DovetailHigh in one directionHigherDrawers, fine boxes

Wood movement matters

Solid wood expands and contracts across its width with changes in humidity, something that is very noticeable through a Canadian heating season. Good joinery either allows for that movement or keeps the moving dimension short. A joint that ignores movement can split a panel or push itself apart over time.

References