DT resources

Hardwoods:

• Beech-finishes well, used for furniture, toys and kitchen utensils.
• Oak-stains on contact with steel, tough, used in the garden.
• Ash-can bend if steamed, used for tool handles and sports equipment.

Softwoods:

• Pine-easy to use, cheap, used for building frames but needs protecting outdoors.
• Cedar-expensive and light but weak, used outdoors.

Manufactured Boards:

• Plywood-veneers glued together, used for furniture and toys
• Blockboard-strips of softwood glued together on sides and veneer covering, strong and stable.
• MDF-a solid and stable board, used for furniture, kitchen units and flooring.
• Chipboard-difficult to join and not very strong, easily damaged by water, used in kitchens.
• Hardboard-Cheap flat board, flexible so needs supporting, used in cupboards backs and drawers.

Ferrous:group of metals that contain iron and varying amounts of carbon. Normally magnetic.

• Cast iron-machinery or car brakes.
• Mild steel-widely available at moderate prices, nails, cars.
• Medium carbon steel-strong and hard, garden tools and springs.
• High carbon steel-very hard and difficult to cut, used for scissors and chisels.
• Stainless steel-very good resistance to corrosion, used for sinks, cutlery dishes etc.
• High speed steel-resistant to friction, very hard, used for drills, lathes, milling cutters.

Non-ferrous:group of metals that do not contain iron, such as gold.

• Copper-good conductor of heat and electricity, used for roofing and electrical equipment.
• Aluminium-strong and light, used for kitchen foil and pans.
• Zinc-very weak and heavy, used for galvanising products  to protect rust.

Alloys:metals formed by mixing two or more metals that has improved characteristics.

• Brass-copper(65%) and zinc(35%) andheavy and hard, used for castings, garden ornaments, taps and valves etc.
• Bronze-copper(80-90%) and tin/nickel/aluminium, used for gears and cast sculptures/statues.

Thermoplastics:become soft and pliable when heated and can be reheated as often as required.

• PET-bottles;moderate chemical resistance.
• HDPE-crates, bowls, pipes; strong and stiff, excellent chemical resistance, easily coloured.
• PVC-pipes, guttering; good chemical and water resistance.
• LDPE-shampoo bottles, toys, carrier bags; tough and flexible.
• ABS-phone cases, safety helmets; high impact strength, lightweight.

Thermosetting plastics:soft and pliable the first time they're heated but a chemical change occurs on cooling and they then become rigid, non-flexible plastics and cannot be reheated and changed.

• Urea formaldehyde-rigid, brittle, heat resistant, conducts electricity; used for plugs and switches.
• Phenol formaldehyde-dark, hard, quiet brittle, very good heat resistance; used for saucepan handles.
• Epoxy resins-good chemical wear and heat resistance, adhesive to many surfaces; surface coatings, adhesives.

Smart Materials:

• Polymorph-reactive capacity is to change from a solid to a mouldable state when warm water (60°C) is applied; comes in plastic granules.
• Thermochromic pigments-added to plastics before moulding; reactive capacity is to change colour when its temperature changes; used for babies spoons.

Nanomaterials:

• There are many nanomaterials being developed in research and development departments all over the world. It is seen as the future of materials development.
• It makes materials lighter, stiffer and stronger to improve the quality of the products.