First Year Engineering
Class Notes and
Homework Workbook
First Year Metalwork
Topics to be covered
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Safety.
Bench tools.
Properties of Materials
Metals.
Drilling
The Centre Lathe.
Joining.
SAFETY
‘Accidents do not just happen,
there is always a cause for them’
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 . . . . . . . . . . . . . . .
Seven Safety Hazards
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Hair – Example: long hair should be tied back.
Eye protection –
Hot metal –
Sharp metal and tools Clean workplace Fire Fumes -
Bench tools
• Bench tools layout
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benct tools dia
Bench tools
• Cold Chisels
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similar to punches
used to cut metal
• Spring dividers
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similar to a compass
used to draw circles.
Set radius using adjusting nut
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puc mark can be used to hold it on the centre
• Engineers tri-square.
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Used to mark lines at 90 degrees on materials.
Used to check corners are square.
Handle called stock other part called blade
• Engineers rule.
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This is a steel ruler.
Only millimetres are to be used
Bench tools
• Cold Chisels
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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
Bench tools
• Bench vice
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made from cast iron
bolted to the table
used with vice clamps (protects the work piece)
• Ball pein Hammer
• name from rounded side
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used with dot punch and chisels only
must be held at the end of the handle
• The scriber
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used to draw lines on the metal
made from carbon steel (wont wear).
• The Dot / Centre punch.
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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)
Properties of Materials
In other word the characteristics
of a particular metal or material. (Or
how that metal/material is different to
others.)
Surface properties
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Colour
Transparent or Opaque
Reflection
Lustre (Also known as shine e.g. gold/silver )
Mechanical properties
• Hardness:
• resistance to scratching or indentation.
Hardness can be tested by:
• Brinell,
• Vickers or
• Rockwell hardness testers.
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.
Electrical properties
• Electrical conductor:
• allows electrical current to flow, e.g.
copper.
• Electrical insulator:
• prevents current flowing, e.g. Polymers
(Polystyrene, polycarbonate, nylon.)
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.
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.