Plastics

Strength

Needs a large amount of force to cause it to deform out of shape

Elasticity

Can be deformed a lot and still return to it's original shape

Hardness

Difficult to scratch or indent

Plastic Properties

Light, Cheap, Weak, Good insulator, Waterproof, Non-corrosion, Non-toxic, Most recyclable, can be transparent

Thermoplastic

Easily melted & reshaped, Weaker than thermosetting, Lower melting point, Most recyclable

Thermoplastic Examples

Acrylic, Polythene, Nylon, PVC, Polystrene

Thermosetting

Cannot be melted & reshaped, Stronger, Harder, Brittle than Thermoplastics, Higher melting point, good insulators, Not Recyclable

Thermosetting Examples

Bakelite, Melamine, Fibreglass, Resin

Orthographic Projection

Orthographic Drawing - Set of 2D drawings

Views drawn at right angles from each other

Top-Down - Plan

Side-on - Elevation

Isometric Drawings

3D Drawings

Vertical shown as vertical, Horizontal lines drawn at 30º to the horizontal

Engineer's Square

Used to draw lines perpendicular to a straight edge

Thick Part - Stock

Thin Part - Blade

Spring Dividers

Mark out circles, semi-circles and arcs

Centre/Dot Punch

Creates a small indent to mark out position of a hole, centre of a circle, mark out a reference point for further measurement and marking out

Bench Vice

Fixed to a workbench, for hand-held operations, twistable screw closes two plates onto workpiece

Machine Vice

Bolted to the worktable of a machine tool

Use soft rubber jaws/pieces of wood to avoid scratching