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A plastic is a man-made material
made from a wide range of
organic polymers such as
polyethylene, PVC, nylon, etc.,
that can be moulded into shape

A polymer is a long chain of
molecules bound together

Organic - Natural
Molecule - A group of atoms bound together

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Brass Copper (60%) + Zinc (40%) Used to make water fittings,
screws, musical instruments, etc.
Bronze Copper (80%) + Tin (20%) Used to make statues, boat

propellers

Solder Lead (70%) + Tin (30%) Used to join metals together and
for joining electrical wires

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Aluminium

A soft metal which is a good
conductor and has a high
resistance to corrosion

Used to make cooking foil, bodies
of cars, window frames, etc.

Copper A very good conductor of
heat and electricity

Used to make water cylinders,
electric wires, etc.

Lead A very soft metal that is

rust resistant Used in car batteries
Zinc This metal is rust resistant Used to galvanise metals
Gold An expensive metal Used to make jewellery

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Mild steel

The most common type of
steel used in the metalwork
room

Used to make boats, bridges, etc.

High Carbon
Steel

Very hard and has good
resistance to wear

Used to make chisels, hammers,
screwdrivers

High Speed
Steel

Very hard and can withstand
heat from friction

Used to make drill bits, hacksaw
blades

Stainless
Steel High resistance to rusting Used to make sinks, cutlery, etc.

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Metals can be broken into
three different families:
1. Ferrous
2. Non-Ferrous
3. Alloys

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Strength A material that cannot be stretched or squashed easily
Hardness A material that will not be marked or scratched easily
Ductile A material that can stretch without breaking
Malleable A material that can be shaped easily
Toughness A material that can withstand hammering without cracking or breaking
Brittleness A material that breaks or shatters easily
Elasticity A material that if stretched, will go back into its original form
Conductivity A material that allows heat or electricity to flow through it
Insulator A material that will not allow heat or electricity to flow through it

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The electric arc furnace works
along the same lines as the stick
welder. Both need the current
jump or arc to produce enough
heat to melt the metal.
A charge of iron and scrap steel is fed into the furnace.
Like the basic oxygen furnace, samples are taken from time to time to check the
quality of the steel.

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The basic oxygen furnace is the most common way in which steel in produced in
the world.

• They are six main steps in how steel is produced in this furnace:

1) First scrap iron and steel are fed into the furnace

2) Molten pig iron is then poured into the furnace
3) The oxygen lance is then lowered into the furnace for
oxygen to be blown in to the furnace to increase the heat.
The oxygen also makes slag in the furnace.
Water runs through the lance to stop it from melting in the
furnace.

4) Samples are taken from time to time to check the quality of the steel.

5) The lance is removed and rolled on its side to allow
the molten iron to
be poured through the tapping hole.

6) Then it is rolled over to allow the slag to be poured out of the slagging hole.

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How do you keep the heat in furnace when loading the charge?
• The same as if you were baking a cake, if you open the oven door during the
baking you will leave all
the heat out.
• On the diagram you see the furnace has a cup and cone (double bells)
arrangement. This is made up of two cones that can be raised and lowered.
• When the furnace is on, both cones are pulled up and the furnace is air-tight.
• When you want to add more charge only the top cone drops down.
• Since the bottom cone is still pulled up the heat has not escaped.
• Once all the charge is loaded in, the top cone is then pulled back up.
• Now the bottom cone is dropped down and all the charge falls into the furnace.
• Once all the charge is in the furnace the bottom cone is pulled back up.

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• Iron comes from the blast furnace.
• A charge made up of iron ore, limestone and coke is put in the furnace.
• Hot air is blown into the furnace by Tuyeres to increase the heat.
• The fire bricks also known as the Refractory Lining help keep the heat in the
furnace.
• As the mixture melts, the molten iron sinks to the bottom of the furnace.
• The limestone makes the waste or Slag float on top of the molten iron.
• The slag is taken out of the furnace from time to time. This can be used as a
fertilizer for farming.
• The molten iron, now known as Pig Iron, is removed from the furnace.

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Excavated  -to dig something up.
Extracted - to take something out.
iron is excavated .
Iron ore is a mix of clay ,rocks ,sand and silt .

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No loose clothing
wear eye protection
wash your hands
clear walkways