Woodworking joints

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Joinery often refers to the part of woodworking that involves the joining together of parts of wood.

Traditional wood joinery techniques address the distinctive material properties of wood, often without resorting to mechanical fasteners. There are different types of joinery for different structures, for example the joinery used to build a house is different from that used to make puzzle toys, although elements overlap.

Wood is anisotropic: its material properties are different along different dimensions. It is strong when stressed along the grain (longitudinally), but weak across it (radially and tangentially). It expands and contracts in response to humidity. This change is very small longitudinally. It is considerable, but unequal, in the radial and tangential directions. The frame and panel constructions of doors and cabinets is not purely decorative. The panel would be fragile without the support of the rails, whose grain runs perpendicular to that of the panel. But, if the rails were directly fastened to the panel, the difference in the rate of expansion across and along the grain would rip the two apart. When properly constructed, the panel is free to expand, while still supported by the frame.

Glue is highly effective for joining wood when both surfaces of the joint are edge grain. A properly glued joint may be as strong as a single piece of wood. However, glue is ineffective on end-grain surfaces. Compared to a mortise and tenon, a dowel joint is a poor joint because it does not address these properties. Much of the surface of the hole of a dowel joint is end-grain, to which glue adheres poorly. In a mortise and tenon, most of the surface of the joint is edge-grain.

Contents 1 Types of joints 1.1 Images of different types of joints 2 Styles of Joinery 3 See also 4 References

[edit] Types of joints

Some types of joints used include:

• Bridle
• Butt
• Butterfly
• Dowel
• Coping
• Cope and stick
• Dado
• Dovetail
• Finger (US) or box combing (UK)
• Lap (halving joint)
  • Cross-lap
  • Halved joint
  • Dovetail-lap
  • End-lap (corner halving joint)
  • Middle-lap (Tee halving joint)
• Miter (mitre)
• Mortise and tenon
• Rabbet (rebate)
• Scarf (scarph)
• Splice joint
• Tongue and groove
• Frame and Panel (rail and style)

[edit] Images of different types of joints

Bridle joint	Dowel joint	Coped joint	Dado
Dovetail joint	Finger joint or box combing	Lap joints	mitre (miter) joint
Mortise and tenon joint	Rabbet or rebate	Scarf joint	Splice joints

[edit] Styles of Joinery

Two of the most common traditions of joinery are Chinese and European. Chinese in particular developed hundreds of types of joints and their furniture was often held together without glue or nails.

[edit] See also

• Woodworking
• Building construction

[edit] References

• Bernard Jones (Ed.) (1980). The Complete Woodworker. ISBN 0-89815-022-1
• Peter Korn (1993). Working with Wood. ISBN 1-56158-041-4
• Sam Allen (1990). Wood Joiner's Handbook. Sterling Publishing. ISBN 0-8069-6999-7
• Wolfram Graubner (1992). Encyclopedia of Wood Joints. Taunton Press. ISBN 1-56158-004-X