First Year Engineering

1. First Year Engineering Class Notes and Homework Workbook

2. First Year Metalwork Topics to be covered • Safety. • Bench tools. • Properties of Materials • Metals. • Drilling • The Centre Lathe. • Joining.

3. SAFETY ‘Accidents do not just happen, there is always a cause for them’

4. Safety in Technical Rooms • My class may not use machines without a teacher in the room. • I may not use equipment that I have not been shown how to use. • All accidents must be reported to the teacher. • Be prepared for class. • I will not be allowed to work if my behaviour puts myself or others in danger. Signed . . . . . . . . . . . . . . .

5. Seven Safety Hazards • Hair – Example: long hair should be tied back. • Eye protection – • Hot metal – • Sharp metal and tools - • Clean workplace - • Fire - • Fumes -

6. Bench tools • Bench tools layout • benct tools dia

7. Bench tools • Cold Chisels • similar to punches • used to cut metal • Spring dividers • similar to a compass • used to draw circles. • Set radius using adjusting nut • puc mark can be used to hold it on the centre • Engineers tri-square. • Used to mark lines at 90 degrees on materials. • Used to check corners are square. • Handle called stock other part called blade • Engineers rule. • This is a steel ruler. • Only millimetres are to be used

8. Bench tools • Cold Chisels • similar to punches • used to cut metal • Spring dividers • similar to a compass • used to draw circles. • Set radius using adjusting nut • puc mark can be used to hold it on the centre • Engineers tri-square. • Used to mark lines at 90 degrees on materials. • Used to check corners are square. • Handle called stock other part called blade • Engineers rule. • This is a steel ruler. • Only millimetres are to be used

9. Bench tools • Bench vice • made from cast iron • bolted to the table • used with vice clamps (protects the work piece) • Ball pein Hammer • name from rounded side • used with dot punch and chisels only • must be held at the end of the handle • The scriber • used to draw lines on the metal • made from carbon steel (wont wear). • The Dot / Centre punch. • Used to mark the centre of a hole for drilling (puc). • Used to mark along a line especially steel. • made from High carbon steel (hardened and tempered)

10. Properties of MaterialsIn other word the characteristicsof a particular metal or material. (Or how that metal/material is different to others.)

11. Surface properties • Colour • Transparent or Opaque • Reflection • Lustre (Also known as shine e.g. gold/silver )

12. Mechanical properties • Hardness: • resistance to scratching or indentation. Hardness can be tested by: • Brinell, • Vickers or • Rockwell hardness testers.

13. Mechanical properties • Malleability: • the ability to be beaten or rolled into thin sheets, e.g. aluminium, copper, etc. • Ductility: • allows a material to be drawn into wire, e.g. copper, brass, steel, etc. • Elasticity: • allows a material to return to it’s original shape after it has been deformed, e.g. rubber.

14. Electrical properties • Electrical conductor: • allows electrical current to flow, e.g. copper. • Electrical insulator: • prevents current flowing, e.g. Polymers (Polystyrene, polycarbonate, nylon.)

15. Thermal properties • Melting point: • the temperature at which a material turns to a liquid. • Thermal conductor: • will transmit heat, e.g. copper. • Thermal insulator: • will slow down or prevent heat from escaping, e.g. polystyrene foam.

16. Mechanical properties • Brittleness: • can be fractured easily by impact, e.g. glass. • Toughness: • can withstand blows or impact. (Hammer blows.) Or tested by Charpy or Izod impact testers. • Strength: • a measure of the ability to withstand forces such as tension, compression or torsion.