Wood, Metal and Plastics
There are three main types of timber: hardwoods, softwoods and manufactured boards. Here are a few examples:
Properties and colour
Metals can either be ferrous or non-ferrous:
★ Ferrous metals contain iron and small amounts of other metals. Almost all ferrous metals are magnetic. But one major disadvantage of many ferrous metals is that they rust and therefore protective coats need to be added.
★ Non-Ferrous metals contain no iron and therefore do not rust like ferrous metals and many do not require a protective coating. However some non-ferrous metals can be expensive and have very versatile characteristics.
Light brown colour. Tough and durable. Finishes well but stains in contact with steel.
Beams used in buildings
Pinkish colour. Close-grained, hard-wearing and strong.
Cream/pale colour. Easy to work and fairly cheap but may contain knots, which will weaken the wood.
Building frames and construction
(but needs protection if used outdoors) Cast-iron
Hard skin with soft core. Strong under compression but cannot be bent.
Heavy crushing machinery
Vice or machine parts
Dark reddish brown colour. Light in weight but expensive.
Not very strong but durable due to natural oils.
Tough, ductile and malleable. Poor resistance to corrosion. It cannot be hardened.
Screws and nails
Malleable, ductile and tough. Good conductor of electricity and heat. Easily joined.
Very weak and heavy. Resists to corrosion however it is difficult to work.
Research and Speciﬁcation
Galvanizing products to protect from rusting
All manufactured boards are made from wood that has been processed. Some use waste materials (chipboard and
MDF) whilst others are cut into veneers and processed to make the boards (plywood). Advantages of using manufactured boards include that they’re available in large sizes, stable and easy to work with however disadvantages include that they can be more expensive and not as attractive.
Has smooth even surface and is easily machines, painted or stained.
Available in water and fire resistant form.
A very strong board, constructed of layers of veneer or plies. Can be used in extreme conditions.
Boat building and exterior work
Alloys are produced by combining pure metals to create new types of metal. Two or more metals are combined to create a new metal with unique characteristics to meet specific demands. Name
Moderate chemical resistance, mainly used in transparent…