A strong joint, the tongue and groove joint is widely used for re-entrant angles. The effect of wood shrinkage is concealed when the joint is beaded or otherwise moulded. In expensive cabinet work, glued dovetail and multiple tongue and groove are used.

Tongue and groove or T&G is a method of fitting similar objects together, edge to edge, used mainly with wood

Wood

Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...

: flooring

Flooring

Flooring is the general term for a permanent covering of a floor, or for the work of installing such a floor covering. Floor covering is a term to generically describe any finish material applied over a floor structure to provide a walking surface...

, parquetry

Parquetry

Parquetry is a geometric mosaic of wood pieces used for decorative effect. The two main uses of parquetry are as veneer patterns on furniture and block patterns for flooring. Parquet patterns are entirely geometrical and angular—squares, triangles, lozenges. The most popular parquet flooring...

, panelling, and similar constructions. Tongue and groove joints allow two flat pieces to be joined strongly together to make a single flat surface. Before plywood became common, tongue and groove boards were also used for sheathing buildings and to construct concrete

Concrete

Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...

 formwork

Formwork

Formwork is the term given to either temporary or permanent molds into which concrete or similar materials are poured. In the context of concrete construction, the falsework supports the shuttering moulds.-Formwork and concrete form types:...

.

Each piece has a slot (the groove) cut all along one edge, and a thin, deep ridge (the tongue) on the opposite edge. The tongue projects a little less than the groove is deep. Two or more pieces thus fit together closely. The joint is not normally glued, as shrinkage would then pull the tongue off.

In another assembly method, the pieces are end-matched. This method eliminates the need for mitre joints, face nailing, and the use of joints on 16-inch or 24-inch centres of conventional framing.

For many uses, tongue and groove boards have been rendered obsolete by the introduction of plywood

Plywood

Plywood is a type of manufactured timber made from thin sheets of wood veneer. It is one of the most widely used wood products. It is flexible, inexpensive, workable, re-usable, and can usually be locally manufactured...

 and later composite wood boards, but the method is still used in higher-quality flooring. Plywood may also be tongued all round to fit it flush into a framed structure, and plywood for sub-floors used in platform framing is often supplied with tongue and groove edges.

When joining thicker materials, several tongue and groove joints may be used one above the other.

Methods

One of the following woodworking tools may be used to produce the tongue and groove:

• A four- or six-head moulder
  Moulder
  A wood moulder is a machine used to shape wood with profiled cutters. The profiled cutters are also known as knives, and blades. Tooling refers to cutters, knives, blades including planer blades, and cutterheads. Most moulders require the blades to be secured into a cutterhead that mounts on the...
  
   (for large quantities)
• A spindle moulder
  Moulder
  A wood moulder is a machine used to shape wood with profiled cutters. The profiled cutters are also known as knives, and blades. Tooling refers to cutters, knives, blades including planer blades, and cutterheads. Most moulders require the blades to be secured into a cutterhead that mounts on the...
  
   (wood shaper)
• A circular saw bench
• Suitable hand planes: a plough plane for the groove and a tongue plane for the tongue, or a combination plane
• A spindle router

Tongue-in-groove

Tongue-in-groove is similar to tongue and groove, but instead of the tongue forming part of one of the edges, it is a separate, loose piece that fits between two identically grooved edges. The tongue may or may not be of the same material as the grooved pieces joined by the tongue. For example, plywood flooring is commonly grooved at the edges, and plastic tongues are used to form the joint.

See also

• Cabinet making
  Cabinet making
  Cabinet making is the practice of using various woodworking skills to create cabinets, shelving and furniture.Cabinet making involves techniques such as creating appropriate joints, dados, bevels, chamfers and shelving systems, the use of finishing tools such as routers to create decorative...
  
  
• Carpentry
  Carpentry
  A carpenter is a skilled craftsperson who works with timber to construct, install and maintain buildings, furniture, and other objects. The work, known as carpentry, may involve manual labor and work outdoors....
  
  
• Fluting (architecture)
  Fluting (architecture)
  Fluting in architecture refers to the shallow grooves running vertically along a surface.It typically refers to the grooves running on a column shaft or a pilaster, but need not necessarily be restricted to those two applications...
  
  
• Gland (engineering)
  Gland (engineering)
  A gland is a general type of stuffing box, used to seal a rotating or reciprocating shaft against a fluid. The most common example is in the head of a tap where the gland is usually packed with string which has been soaked in tallow or similar grease...
  
  
• Groove (joinery)
  Groove (joinery)
  In joinery, a groove is a slot or trench cut into a member which runs parallel to the grain. A groove is thus differentiated from a dado, which runs across the grain....
  
  

• Nipple (disambiguation)
  Nipple (disambiguation)
  Nipple may refer to:* The nipple, in human or mammalian anatomy* The flexible nozzle on a baby bottle simulating a human nipple* A nipple , which is a type of pipe fitting* Nipple , an album by the Claw Boys Claw...
  
  
• Parquetry
  Parquetry
  Parquetry is a geometric mosaic of wood pieces used for decorative effect. The two main uses of parquetry are as veneer patterns on furniture and block patterns for flooring. Parquet patterns are entirely geometrical and angular—squares, triangles, lozenges. The most popular parquet flooring...
  
  
• Slot
  Slot
  Slot may refer to:* A narrow opening through which an object can pass, for example in a:** Vending machine slot** Slot machine, a type of casino game* Slot, a space for a container on a ship, usually expressed as a 20' or 40' slot Slot may refer to:* A narrow opening through which an object can...
  
  

• Tongue (disambiguation)
  Tongue (disambiguation)
  Tongue most generally refers to the muscle on the floor of the mouth. By analogy or other figure of speech it can also refer to:*Part of a shoe that covers the foot underneath the laces*Part of a trailer tow hitch attachment...
  
  
• Wood router
  Wood router
  A router is a tool used to rout out an area in the face of a relatively hard workpiece, typically of wood or plastic. The main application of routers is in woodworking, especially cabinetry....
  
  
• Woodworking
  Woodworking
  Woodworking is the process of building, making or carving something using wood.-History:Along with stone, mud, and animal parts, wood was one of the first materials worked by early humans. Microwear analysis of the Mousterian stone tools used by the Neanderthals show that many were used to work wood...
  
  
• Woodworking joints
  Woodworking joints
  Joinery is a part of woodworking that involves joining together pieces of wood, to create furniture, structures, toys, and other items. Some wood joints employ fasteners, bindings, or adhesives, while others use only wood elements. The characteristics of wooden joints - strength, flexibility,...