What can you remember Different Materials have Different

What can you remember. . . ?

Different Materials have Different Properties Strength Hardness Brittleness Plasticity Toughness Durability

Strength Ability to withstand force without braking. Hardness Ability to withstand scratching, rubbing or denting. Plasticity Ability to change shape permanently without breaking or cracking. Brittleness Materials that can’t withstand much pressure. More like to crack or break. Toughness Opposite to brittleness. Can absorb impacts without breaking or snapping. Durability Materials that are able to withstand repeat use. Withstand wear and tear.

Strength Hardness Plasticity Brittleness Toughness Durability

Strength Hardness ? Plasticity Brittleness Toughness Durability

Timber

Timber is the general name used for wood materials. There are three main types of timber: - Softwoods Hardwoods Manufactured boards

Softwoods come from coniferous trees which are ever green and have needles or cones instead of leaves. They are fast growing which makes them cheap. Main examples of softwoods are: • Pine • Fir • Cedar

Hardwoods come from deciduous trees, which have broad flat leaves. Hard wood trees loose there leaves in autumn. They are slow growing which makes them expensive. Main examples of hardwoods are: • Oak • Mahogany • Beech • Teak

Manufactured boards are man made and made from • gluing together layers of wood • gluing and compressing wood chippings or dust together. Main examples of manufactured boards are: • Plywood • MDF • Hardboard

Different timbers and their properties Softwood timber Properties Use Pine Soft, easy to work with, accepts paint and stain, can have knots which provides difficulties when cutting Interior joinery, Fir Strong and elastic, resistant against fungal and insect infestation, has good natural durability when exposed to the weather Building / construction work Hardwood timber Properties Use Mahogany Expensive but easy to work with, dark in colour, has an attractive look Fine furniture Teak Hard, weather resistant Garden Furniture, window frames Beech Hard and tough but can be worked easily, has high scratch resistance, but can shrink considerably Chairs and toys Manufactured timber Properties Use Plywood Strong, can be bent, can be finished with a nice veneer Building / construction work, curved furniture Chipboard Not very strong, cheep, but is resistant to warping and will not splinter Table tops and cheep furniture MDF Cheep, more dense and strong than chipboard, has smooth faces and takes paint and other finishes well Shelves and furniture Hardboard Cheep, thin and more dense than MDF Cupboard backs and draw bottoms