Wood Joints Flashcards
What is an addition process?
Products that are made by joining wood with other pieces of wood. (1)
What is a fabrication process?
Products are fabricated using traditional wood techniques (1) or knock-down (KD) fittings. (2)
What is a KD fitting?
Range of standardised fittings often used in flat-pack furniture or other wooden structures assembled with basic tools (1). They enable manufacturers to supply products which are not assembled. This reduces cost for the manufactures and customer (2). Storing and transporting the products become much easier therefore reducing manufacturing time (3). For the customer KD fittings are relatively easy to use with a limited number of simple tools (4). Flat pack furniture is usually easier to carry through store doors rather than it being ready made (5).
What is a butt joint?
Two pieces of timber are joined relying on an adhesive such as PVA (1). It is only suitable for lightweight applications such as modelling (2). Once the PVA is applied the joint is then clamped until dry (3).
What is a dowel joint?
A dowel joint is measured and the position is marked for the dowel (1). The holes are then drilled and glue is put in the holes before the dowels are hammered (knock-down fitting) into position (2) and pieces are clamped together (3). They are usually used in flat pack furniture (4).
What is a dowel?
Dowels are small round pegs made from a hardwood (1). Their diameters range for timbers of different thicknesses (2). Some machines are machined with grooves that allow wood to flow up the dowel when hammered into place (3).
What is a mitre joint?
Pieces are cut to 45 degrees and join together to make a 90 degree corner (1). They are then glued and clamped using a mitre jig to keep the corners straight (2). The main use for a mitre jig is to make picture frames (3).
What is a comb joint?
Two pieces are interlocked to make an application e.g. a box (1). The combs ‘teeth’ allow for increased gluing surface area making the joint very strong (2). Combs can be cut with relative ease using a bandsaw, laser cut or tenon and saw and wood chisel (3).
What is a dovetail joint?
Dovetail joints are cut with a dovetail saw or machined with a router and jig (1). They are in the shape of a trapezium without the top. They are great for applications such as drawers due to their directional strength - once glued together they are impossible to pull apart (2).
What is a mortise and tenon joint?
A square or rectangular hole is cut into a piece typically by a mortise machine or router, or simply drilling and chiselling rough edges (1). The second piece of timber is the cut using a tenon saw or band saw to make the tenon (2). PVA glue is spread into the mortise and two parts are clamped together (3). This joint is used for heavy duty frame construction applications (4).
What is a housing joint?
A groove is cut across one piece and the end of the other piece can be inserted into it (1). It can be glued to make a permanent joint or left so it ca be adjusted to be slid in and out (2). They are typically structurally strong and used to make cabinets, shelving (framework construction) (3).
Can be cut using a router or a tenon saw and chisel (4).
What is a half lap joint?
A step is cut into the end of each piece (1). The larger surface area on each cut piece means it is stronger than a regular butt joint (2). It can be used for simple frames and boxes. These joints are easy to mark and cut with a tenon saw or band saw (3).
What are modesty blocks?
Small, rigid, polymer blocks which have moulded holes that take screws which are used to join the block to panels (1). Typically used on cupboards and storage units (2). They aren’t particularly strong or aesthetically pleasing so have become outdated in mainstream furniture (3).
What is a Barrel nut and bolt?
A common knock-down fitting is the barrel nut and bolt. It uses a cross dowel which is fitted into one of the pieces (1). A bolt is then inserted through the other piece of timber and tightened into the cross dowel (often using an Allen key) (2).
These are often used to assemble parts of flat-pack furniture such as the frame of a bed or table (3).
What is a cam-lock connector?
A cam-lock connector consists of of a metal dowel that is screwed into one of the pieces by inserting a screw driver into the slot on side (1). The cam is a disk that fits into a pre -drilled hole in the other piece (2). When the disk is rotated with a screwdriver , the collar on the dowel locks into the cam and pulls both pieces tightly together (3).
What are bolts?
Bolts that are used to join wood pieces together - called ‘coach bolts’ - have a thread that runs about two-thirds of the way along the bolt (1). Under the domed head of the bolt is a square piece that digs into the wood when tightened, preventing the bolt from rotating (2). This means that when the bolt is tightened, the domed head cannot be undone with a spanner (3).
Wood screws
When joining two pieces of wood together, the top part is drilled with a clearance hole that the screw simply pushes through (1). The bottom piece of timber has a pilot hole (thinner than the thread) so that the coarse pitch of the thread bites into the timber (2).
- Slot head
- Philips
- Pozidriv (3)
