Components: 1

Resistant materials components are usually bought ready-made. The most common components you need to know about are nails, screws, hinges and catches.

The main types of component are:

• threaded fastenings, including wood screws, machine screws, nuts and bolts, and self-tapping screws
• rivets, including hammered rivets and pop rivets
• hinges, catches and locks
• knockdown fittings

• 

  Nails

  Nails are generally used where appearance is not important, or where a quick job is needed. Panel pins and veneer pins are used to fix backs onto cupboards and bottoms onto boxes. Veneer pins are finer (or thinner) than panel pins. Nails and pins are usually made of mild steel.

• 

  Screws

  Wood screws are used to join metal or plastic components to wood, or to join two pieces of wood to make a strong joint.

• 

  Machine screw

  Machine screws have a screw thread to fit into a threaded hole or a hexagonal nut. They can be used to join two or more pieces of metal or plastic.

• 

  Bolt

  Bolts have a screw thread which fits into a threaded hole or a hexagonal nut, and are normally used to join two or more pieces of metal or plastic. A bolt is only threaded for part of its length. Bolts normally have hexagonal heads.

• 

  Set screw

  Set screws have a screw thread along the whole or most of their length, and normally have hexagonal heads.

Components: 2

• 

  Rivets

  Hammered rivets are used to join metal, but are sometimes used on products such as kitchen knives, where a wooden or plastic handle may be riveted to the blade.

  The soft metal shaft of the rivet is passed through a hole drilled in the material to be fixed. Then, while the head is held tightly in place on the other side, the shaft is hammered flat to form a secure joint.

• 

  Pop rivet

  Pop rivets were originally designed for use in the aircraft industry but are now used in many different products. They are often used where there is only access to one side of the material - eg fixing to a metal tube.The body of the rivet is inserted into a hole drilled into the material to be fixed, and when the pin is gripped and pulled by a special tool it pulls and expands the body to form a solid joint on both sides of the hole.

• 

  Hinges, catches and locks

  Hinges, catches and locks are used on boxes, cabinets and cupboards. There are many different types in all three categories, and they can be used on products made from wood, metal or plastic. They are normally fixed to the product with wood screws or machine screws and nuts.

• 

  Knock down (KD) fittings

  Knock down (KD) fittings are used where something has to be taken apart often, or which is designed for assembly by the user, such as kitchen units or self-assembly furniture. They are often plastic fittings which can be joined with one screw or bolt.

Adhesives

Adhesives are used to join materials by gluing. Different types of adhesives are used for different materials - for example, if a product is to be used outside, then waterproof adhesives should be used. In the exam you should use the name of the type of adhesive, rather than the product name - eg PVA glue, not Evostick Resin W.

Rules for making a well-glued joint

• the surfaces to be joined must be clean and free of dust and grease
• the joints must fit closely together
• if the adhesive needs to be mixed, this must be done in the correct proportions, and
• with most adhesives, the joint should be held together by clamps or weights until the glue has dried.

Adhesive types

The main types of adhesive are PVA (polyvinyl acetate), synthetic resin, epoxy resin, contact adhesive and acrylic cement.

Uses of adhesives

Now try a Test Bite