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First Year Engineering

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Title: First Year Engineering


1
First Year Engineering
  • Class Notes and Homework Workbook

2
Second 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 - 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 Materials
11
Surface properties
  • Colour
  • Transparent or Opaque
  • Reflection
  • Lustre

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 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 its 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. pvc.

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 by impact, e.g. glass.
  • Toughness
  • can withstand blows or impact, it is tested by
    Charpy or Izod testers.
  • Strength
  • a measure of the ability to withstand forces such
    as tension, compression or torsion.

17
Metals
  • Ferrous Metals
  • Non-ferrous Metals
  • Alloys.

18
Useful Terms for metals
  • Ferrous Metals.
  • Any metal that contains iron is a ferrous metal.
  • Non ferrous metals.
  • This is any metal that does not contain iron.
  • An alloy.
  • This is a mixture of two or more metals.
  • The charge.
  • These are the materials that are put into the
    furnace to produce the metal.
  • The operation (smelting).
  • This is how the furnace works how it makes the
    metal.
  • The products.
  • These are the materials that come out of the
    furnace.

19
Ferrous Metals.All metals that contain iron
are ferrous metals
20
Blast furnace
  • The blast Furnace.

21
Blast furnace
  • Charging bells

22
Blast Furnace
  • The Charge
  • iron ore,
  • coke,
  • limestone.
  • Operations
  • the charge is loaded into the furnace using the
    charging bells. The coke burns when hot air is
    blown in through the tuyere the blast and the
    impurities mix with the limestone to give slag.
    The slag is taken off leaving molten iron to be
    tapped off.
  • The Products
  • molten iron,
  • Slag
  • waste gasses

23
Basic Oxygen Furnace.
  • The basic Oxygen Furnace.

24
Basic oxygen Furnace
  • Stages in Production.

25
Basic oxygen Furnace.
  • The charge
  • Molten Iron and
  • scrap steel
  • limestone
  • The operation
  • charging
  • the blow (water cooled oxygen lance)
  • sampling
  • tapping (molten steel)
  • emptying slag
  • The products
  • molten steel
  • slag
  • waste gasses

26
Basic oxygen furnace
  • The Charge
  • molten iron
  • scrap steel
  • limestone.
  • Operations
  • Scrap charging
  • molten iron charging
  • oxygen lance lowered in (water cooled.
  • The blow
  • sampling
  • slagging
  • tapping
  • The Products
  • molten steel,
  • Slag
  • waste gasses

27
Basic oxygen Furnace.
  • The charge
  • Molten Iron and
  • scrap steel
  • limestone
  • The operation
  • The furnace is charged firstly with scrap steel.
    Molten iron from the blast furnace is then
    charged.
  • The oxygen lance is then lowered in and oxygen is
    blown in causing the impurities and extra carbon
    to mix with the limestone making slag. The lance
    is kept cool with water. The steel is sampled to
    check for the right amount of carbon. The furnace
    is tilted and the molten steel poured out through
    the tapping hole. The slag is then emptied out
    the top.
  • The products
  • molten steel
  • slag
  • waste gasses

28
Electric Arc Furnace.
  • The electric arc furnace.

29
Electric arc furnace
  • The Charge
  • molten iron
  • scrap steel
  • limestone.
  • Operations
  • the lid containing the electrodes are lifted off
    the furnace and the furnace is charged. The lid
    is replaced and electricity is passed down the
    rods. This jumps from the rods to the metal
    causing it to melt. The impurities mix with the
    limestone to form slag. The slag is taken off.
    The furnace is then rotated on the rollers and
    tapped.
  • The Products
  • molten steel
  • slag.

30
The Electric Arc.
  • The charge
  • Molten Iron and
  • scrap steel
  • limestone
  • The operation
  • the carbon rods and roof are lifted off. The
    furnace is charged. The rods are lowered and an
    arc is made between the charge and the rods
    producing heat. The steel is sampled. The furnace
    is on rollers and is tilted for slagging and then
    tapping.
  • The products
  • High Quality molten steel
  • slag

31
Non Ferrous Metals.
  • Aluminium.
  • This is silver in colour, it is very strong
    but light and is malleable and ductile. It is a
    good conductor of heat and electricity. An oxide
    forms on the outside preventing corrosion. It is
    used for aircraft bodies, drinks cans, high
    tension wires.
  • Copper.
  • This is reddish brown in colour and is
    malleable and ductile. It is a good conductor of
    heat and electricity. It turns green as it
    corrodes. It is used in electrical wiring,
    heating pipes and for roofing.

32
Non Ferrous Metals.
  • Lead.
  • This is a very heavy metal, it is a dull grey
    colour and is flexible at room temperature. It is
    poisonous if handled to often. It is used for
    making batteries and also for roofing.
  • Zinc
  • This is a grey colour. It does not corrode
    easily and so it is used for galvanizing (coating
    steel) to stop rusting.
  • Tin
  • This is a silvery white metal, it is weak and
    generally combined with other metals.

33
Alloys.
  • An alloy is a mixture of two or more metals.
    Steel is one example.
  • Brass.
  • This is a combination of copper and zinc. It
    is a gold colour and does not rust easily. It is
    used to make hinges, screws, outside taps and
    musical instruments.
  • Bronze.
  • This is a combination of copper and tin. It is
    a dark green colour and is easily cast making it
    ideal for statues.
  • Soft solder.
  • This is a combination of lead and tin. It has
    a very low melting point and so it can be used to
    join electronic components.

34
Machine tools
  • The Pillar drill.
  • The Centre lathe.

35
The Pillar Drill.
36
The Pillar Drill
  • The Base
  • this is made from cast iron and is bolted to the
    floor. It can be used to support large pieces
    when drilling.
  • The column
  • This is attached to the base and supports the
    table as well as the motor spindle and the gears.
  • The table.
  • This is attached to the column and can be moved
    up or down and can be rotated.
  • The chuck
  • This is connected to the spindle and is used to
    hold parallel shank drills. The chuck is
    tightened using the chuck key.

37
The Pillar drill.
  • The Feed Lever.
  • This moves the drill to and from the piece.
  • Adjustable depth stop.
  • This is used to set the required depth of the
    hole. It stops the drill going all the way
    through the piece unless required.
  • The Motor.
  • This takes electricity and turns it into rotary
    motion powering the spindle.
  • The spindle and gears.
  • Different gears are needed for different jobs.
    The gears are connected to the motor and the
    spindle allowing it to turn at different speeds.

38
The Pillar drill.
  • Using the Drilling Machine
  • make sure long hair is tied back.
  • have no loose clothing.
  • Always wear safety glasses.
  • Never use the machine if the teacher is not
    present.
  • make sure the work is properly held.
  • make sure the drill speed is correct.
  • Have a dot punch in the center of the hole and
    center the drill on it.
  • Make sure not to pull the feed lever to hard when
    breaking through the piece
  • never drill into the table or machine vice.
  • Always check the drill size before drilling.

39
The Pillar drill.
  • Holding the work for drilling.
  • The machine vice.
  • This is the most common way of holding work. The
    piece should be clamped by two square edges and
    supported by wood underneath. The piece must be
    held level to ensure a round hole.
  • The machine table.
  • The machine table can be used to hold larger
    heavier work. The piece can be bolted to the
    table using clamps. The table can be lowered and
    rotated for difficult pieces.
  • The base.
  • The base can also have pieces bolted to it but
    this is unusual.

40
The Pillar drill.
  • Pilot hole.
  • This is used before drilling a large hole so as
    to keep the drill centred.

41
The Pillar drill.
  • Tapping hole.
  • This is drilled before threading a hole. The hole
    must be smaller than the tap being used.

42
The Pillar drill.
  • Clearance hole.
  • This hole is slightly larger than the bolt or bar
    passed through it.

43
The Pillar drill.
  • Blind hole.
  • This is a hole that does not go all the way
    through a piece.

44
The Pillar drill.
  • Countersink hole.
  • This enlarges the top of the hole and allows the
    head of a screw to sit in flush to the piece.

45
The Pillar drill.
  • Counterboring.
  • This also enlarges the top of the hole to allow
    cheese head screws to fit in flush to the piece.

46
The Pillar drill.
  • Parts of the drill bit.
  • The point angle of a drill bit is 118 degrees.
  • jc79

47
The Pillar drill.
  • Types of drill bit.
  • The Parallel shank.
  • This is used mostly for small size drills and is
    held in a chuck.
  • Morse taper shank.
  • This is used for larger drills and fits directly
    into the spindle or the tailstock of the lathe.
  • A drift is used to remove the drill from the
    spindle.

48
The Pillar drill.
  • The drill gauge.
  • This is a flat steel sheet with different sized
    holes and is used to measure the drill bits.

49
The Pillar Drill.
  • Reamer.
  • The reamer is used to finish a drilled hole.
    The reamer gives the exact size hole, more
    rounded and a better surface finish.

50
The Centre Lathe.
  • The lathe is used to produce cylinders and other
    operations such as drilling on round bars. This
    is known turning.
  • Other shapes that can be worked include square
    and hexagonal bar.
  • The lathe can work with most metals as well as
    polymers (plastic).

51
The Centre lathe
  • diagram of lathe

52
The Centre lathe
  • The Headstock.
  • This part of the machine contains the motor and
    the gearbox. The spindle is connected to the
    gearbox. The spindle is hollow to allow long bars
    pass through.
  • The tailstock.
  • This mounted on the slideways and can be clamped
    in any position. It is used for drilling and also
    in holding long bars.
  • The slide ways.
  • These are similar to train tracks and are
    machined into the lathe bed. They guide the
    tailstock and the carriage along the bed.

53
The Centre lathe
  • The lathe bed.
  • This is made from cast iron as it is easily cast,
    a natural lubricant and it absorbs vibration
    giving a better finish. The bed sits on top of a
    stand and supports the carriage and tailstock.
  • diagram page 143

54
The Centre lathe
  • The carriage.
  • This moves between the head stock and the
    tailstock. It is made up of the saddle and apron.
    It is used to take sliding cuts.
  • The Cross slide.
  • This is attached to the saddle. It moves the tool
    at 90 degrees and is used for taking facing of
    cuts.
  • Top slide / compound slide.
  • This is attached to the cross slide and can be
    set to any angle. It is used to cut tapers on the
    work.

55
The Centre Lathe
  • The Feed Shaft.
  • This allows the carriage and cross slide to be
    moved automatically.
  • The Lead screw.
  • This is used for screw cutting on the lathe.
  • The tool post.
  • This holds the cutting tool or tool holder in
    place.

56
The Centre Lathe
  • Safety on the Lathe.
  • Glasses must be worn at all times.
  • Long hair and loose clothing must be tied back or
    tucked away.
  • Never use the machine if the teacher is not in
    the room.
  • Never use the machine to do something unless you
    have been shown how to do so and you are sure you
    know how to use it.
  • Never leave the chuck key in the chuck.
  • Never have the work touching anything when
    starting the machine.
  • Never check the work when the machine is moving.

57
The Centre Lathe.
  • Make sure that the work is held tightly and is
    centred in all three jaws before starting the
    machine.
  • Never handle swarf as it is extremely sharp.
  • After you have finished clean the machine down
    and move the tool away from the chuck.
  • accidents do not happen they are caused.

58
The Centre Lathe.
  • Spindle speeds.
  • Different speeds are required for different
    operations depending on the condition of the
    lathe.
  • Factors that effect spindle.
  • The diameter of the work.
  • The material being turned.
  • The type of cutting tool.
  • The type of operation.
  • The condition of the lathe.
  • Use of coolant.
  • Method of holding the work.

59
The Centre Lathe
  • Calculating Spindle speed.
  • This can be calculated using the following
    formula
  • N S x 1000
  • ? x D
  • N rotation speed / spindle speed.
  • S cutting speed (given in chart).
  • D Diameter of the bar or work piece.
  • ? 3 or 22
  • 7

60
The Centre Lathe.
  • Worked Example.
  • Calculate the spindle speed required to turn a
    25mm round mild steel bar.
  • N S x 1000
  • ? x D
  • N ? S 30 ? 3 D 25.
  • N 30 x 1000
  • 3 x 25.
  • N 30000
  • 75.
  • N 400 rpm.
  • The spindle speed is set at 400 on the lathe.

61
The Centre Lathe.
  • Toolposts
  • There are three different type of tool post
    available
  • The four way toolpost.
  • This can hold up to four tools at a time. The
    tools are clamped by three locking bolts making
    it very secure. The different tools can be
    rotated into position quickly but changing the
    tools in the holder takes time.
  • jc145

62
The Centre Lathe
  • The American tool post.
  • This can only hold one tool at a time but the
    tool height can be adjusted quickly. The tool is
    held by only one bolt which can lead to chatter.
  • jc145

63
The Centre Lathe.
  • The Universal toolpost.
  • This is similar to the American toolpost. The
    tool height cannot be adjusted quickly and it is
    not suitable for heavy work.
  • Universal toolpost

64
The Centre Lathe
  • Tool types.
  • Tool bit.
  • This is the one used in the engineering
    workshop. The tool is ground from high speed
    steel to the correct angles and held in the
    toolpost. Smaller tools can be held in a tool
    holder.
  • Tipped tool.
  • This is the typed of tool used on the cnc
    machine. A tungsten carbide tip is clamped to the
    tool holder. This tip can be replaced when blunt.

65
The Centre Lathe
  • Operations on the Lathe.
  • Facing off (surfacing).
  • jc149
  • This operation produces a flat surface on the end
    of the bar. The tool is moved using the cross
    slide.

66
The Centre Lathe
  • Sliding cuts (parallel turning).
  • jc149
  • This operation is used to reduce the outside
    diameter of the bar. The carriage is used to do
    this.

67
The Centre Lathe
  • Taper turning (Topslide)
  • lc250
  • Here the topslide is set to the angle required
    and the tool is moved by the topslide giving a
    cone shape to the end of the bar

68
The Centre Lathe
  • Taper turning (off-set tailstock).
  • lc251
  • Here the tailstock can be set to give the taper.
    It is ideal for long tapers but is not possible
    in the workshop.

69
The Centre Lathe
  • Taper turning (attachment).
  • lc254
  • This is a tool that is attached to the carriage.
    It is set as required and moves the tool at the
    required angle as the carriage moves.

70
The Centre Lathe
  • Knurling.
  • jc151
  • This operation is carried out at a very slow
    speed. It is used to cut lines that cross each
    other into the bar. This produces a grip on the
    bar as seen on a scriber.

71
The Centre Lathe
  • Drilling.
  • jc151
  • This is carried out using the tailstock. Small
    drills are held in a chuck while larger drills
    are Morse taper and are held directly in the
    tailstock. A centre drill or slocombe drill is
    used to find the centre.

72
The Centre Lathe
  • Centre Drill.
  • This locates the centre of the bar for frilling
    and acts as a pilot hole for normal drills.

73
The Centre Lathe
  • Parting off.
  • jc 152
  • Here the part is cut or parted off from the rest
    of the bar. It is important to be very careful
    here as the part to fly or be damaged as it drops.

74
The Centre Lathe
  • Under cutting.
  • Jc 152
  • This is very similar to parting off accept that
    the tool only moves in part of the way. It is
    used when screw cutting on the lathe.

75
The Centre Lathe
  • Holding long bars.
  • jc153
  • Long bars are held between centres. A rotating
    centre is placed in the tailstock. The bar is
    held in the chuck or as in the diagram .

76
The Centre Lathe
  • A mandrel.
  • lc268
  • This is used to hold a piece with a hole in the
    centre and where it is necessary to machine the
    whole of the outside of the part.

77
The Centre Lathe
  • Travelling Steady.
  • lc268
  • This is attached to the carriage and moves along
    with the cutting tool preventing a long bar from
    deflecting as it is cut.

78
The Centre Lathe
  • Fixed steady.
  • Lc 269
  • This clamped to the bed of the late and the bar
    is supported on three sides preventing it from
    deflecting.

79
The Centre Lathe
  • Capacity of the lathe
  • lc264.

80
Metal Joining
  • Metal joints can be temporary or permanent.
  • Temporary joints include nuts and bolts magnetic
    catches and compressions joints as in wheel
    bearings.
  • Permanent joints include riveting, soldering,
    welding and adhesives.

81
Mechanical Joining.
  • This refers to joining materials using nuts,
    bolts and rivets.
  • There are four different thread types or forms.

82
Mechanical Joining.
  • The different parts of the isometric thread can
    be seen below.
  • When looking at working drawings the size of the
    thread to be used will be given as M.5 or M.6.
    The M. stands for metric meaning every dimension
    is in millimeters. The number gives the actual
    size of the finished thread .or the outside
    diameter.

83
Mechanical Joining.
  • Bolts

84
Mechanical Joining.
  • Nuts.

85
Mechanical Joining.Internal threading
  • Holes can have threads cut into them allowing
    parts to be joined together, this is called
    tapping.
  • There are three types of tap
  • Taper Tap.
  • This is used to start of the threads in the hole
    or to thread thin sheets. The first 5-6 threads
    are tapered making it easy to start the tap.
  • Second tap.
  • This is used after the taper tap and is used to
    finish of the threads in deeper holes.
  • Plug tap.
  • This tap has threads all the way down and is used
    to thread blind holes.
  • When threading a hole it must be drilled smaller
    than the tap to be used. When drilling you should
    refer to the chart next to the drilling machine

86
Mechanical Joining.
  • Tap and wrench.

87
Mechanical Joining.External threading
  • Bars or shafts can have threads cut into them
    using split dies.
  • Here the die is placed in a stock. The top of the
    bar is usually tapered making it easy to start
    cutting the threads. When starting the thread it
    is important to start the thread straight so as
    to cut a square thread.
  • The split die has writing on one side and this
    must be face down when threading.
  • Hard materials such as steel require oil or
    grease to be used to lubricate the cutting
    process.
  • When cutting threads on a bar or shaft the bar
    must be the same size as the split die being
    used. For example cutting an M10 thread requires
    a diameter 10 bar.

88
Mechanical Joining.
  • Split die and stock.

89
Mechanical Joining. Riveting
  • Rivets can be solid or pop rivets.
  • Solid rivets come in four different forms Round
    or snap, countersunk, pan or flat head.
  • Solid rivets form a very strong joint and were
    commonly used in producing gates, ships and
    bridge panels.
  • Pop rivets are much more common now. They are
    used in the manufacture of aero planes and are a
    very quick way to join materials.

90
Mechanical Joining. Riveting
  • page 97

91
Thermal Joining Soft Soldering
  • Solder is an alloy of lead and tin. It melts at a
    temperature of only 183 degrees c.
  • Solder is mainly used for electronic circuits and
    to join copper pipes.
  • Soft soldering is not a very strong joint as
    solder is a soft metal.

92
Thermal Joining Fluxes.
  • Fluxes are used to remove oxides from the surface
    of the parts being joined together. This ensures
    that the joint between the pieces are a good
    quality.
  • There are two different types of flux passive and
    active flux.
  • Active Flux.
  • Active fluxes remove oxides from the surfaces of
    the parts and also prevent any oxidation when the
    soldering is taking place. The parts must be
    washed well afterwards to remove any remaining
    flux.
  • Passive flux.
  • Protective fluxes prevent oxidation during
    soldering but they do not clean the surfaces
    first. They are used for electrical work and
    anywhere that the parts cannot be washed
    afterwards.

93
First Year Metalwork.Workbook.
94
First Year Metalwork.Workbook.
  • Rules for homework
  • 1. Take down the question in red and write your
    answers in blue or black.
  • 2. Leave space after each question for giving the
    answer.(5 lines)
  • 3. All diagrams should be drawn with a pencil and
    ruler.
  • 4. All homework to be written in the homework
    copy.
  • 5. Homework copies will be collected and signed
    by the teacher each week if you do not have your
    copy it is assumed you do not have your homework
    complete.

95
Homework Sheet 1. Safety.
  • How should we enter the room and why?
  • How do we move around the metalwork room safely
  • Why is it important to keep your desk area tidy?
  • List five safety precautions or rules necessary
    when using a machine?
  • Why is it necessary to return the tools to the
    tool press at the end of class?
  • Why do we brush down the vices and never blow the
    filings?
  • After tidying your desk, what do you do before
    returning to your seat?
  • When leaving the room you have to lineup. What is
    the reason for this?
  • If the fire alarms sounds what are you supposed
    to do?
  • Finish the sentence, accidents do not happen
    they are .

96
Homework Sheet 2. Bench Tools
  • Draw the tools into your copy and name all the
    tools.

97
Homework Sheet 3. Bench Tools
  • 1. What is the bench vice made from?
  • 2. What do we use a scriber for?
  • 3 .What is the scriber made from and why?
  • 4. What tool do we use to scribe circles on
    metal?
  • 5. What is a dot punch used for?
  • 6. What tool is used to draw straight lines on
    the metal and also used to make sure the edges
    are square?
  • 7. What tool is used to prevent the vice jaws
    damaging the work piece.
  • 8. A hacksaw is used for cutting large work what
    tool is used to cut smaller work.
  • 9. Why is it important not to move around the
    room with tools.
  • 10. Why must all the tools be put away properly
    at the end of class

98
Homework Sheet 4. Blast Furnace.
  • Draw the diagram and name the parts.

99
Homework Sheet 5. Blast Furnace.
  1. What is meant by the charge for the furnace?
  2. What is the charge for the blast furnace.
  3. Where does the heat for the furnace come from?
  4. The charging bells allow the charge into the
    furnace and stop heat getting out. How?
  5. What materials are produced in this furnace and
    what are they used for?
  6. How is the slag removed from the furnace?
  7. What is the purpose of the tuyere?
  8. What are ferrous metals?
  9. What happens to the waste gasses produced in the
    furnace?
  10. What is meant by the word tapping?

100
Homework Sheet 6. Basic Oxygen Furnace.
  • Draw the diagram and name the parts.

101
Homework Sheet 7. Basic Oxygen Furnace.
  • 1. What is the charge for the basic oxygen
    furnace?
  • 2. What part of the charge is put into the
    furnace first?
  • 3. What is the oxygen lance used for?
  • 4. How is the lance kept cool?
  • 5. List the six steps in the production of the
    steel?
  • 6. Why do we have to take a sample of the steel?
  • 7. How is the slag removed from the furnace?
  • 8. How is the steel removed from the furnace?
    What is this called?
  • 9. What two materials are mixed together to
    produce the steel.
  • 10. What type of metal is steel ferrous or non
    ferrous?

102
Homework Sheet 8. Electric Arc Furnace.
  • Draw the diagram and name the parts.

103
Homework Sheet 9. Electric Arc Furnace.
  1. What is the charge for the electric arc furnace?
  2. Where does the heat for this furnace come from?
  3. How is this furnace charged?
  4. What are the steps in how this furnace works?
  5. How is the slag removed from the furnace?
  6. How is the steel removed from the furnace?
  7. What is the purpose of the rollers under the
    furnace?
  8. What advantage does this furnace have over a
    basic oxygen furnace?

104
Homework Sheet 10. Ferrous Metals
  • Name three types of ferrous metals?
  • Name the two materials combined to make steel?
  • What is the difference between cast iron and
    steel?
  • Give three uses for cast iron?
  • Give three uses for steel?
  • What is galvanized iron made from?
  • What is rusting?
  • Why do we coat steel with zinc?
  • Name two other ways to stop ferrous metals from
    rusting?
  • What is pig iron also known as?

105
Homework Sheet 11. Steels.
  1. What are the two materials that make up mild
    steel?
  2. Give three uses for mild steel?
  3. What is high carbon steel and what is it used
    for?
  4. What is silver steel made from?
  5. What is it used to make?
  6. What is tinplate, what is it used for?
  7. What is galvanized iron?
  8. What is high speed steel and what is it used for?
  9. What is stainless steel made from?
  10. What is stainless used for and why?

106
Homework Sheet 12. Non-Ferrous Metals and
Alloys.
  • 1. What is a non-ferrous metal.
  • 2. List five non-ferrous pure metals?
  • 3. Give a use for each of the above metals?
  • 4. What is an alloy?
  • 5. Why are alloys generally used instead of pure
    metals?
  • 6. List three non-ferrous alloys?
  • 7. State a use for each of the alloys above?
  • 8. Non-ferrous metals do not rust but they do c_
    _ _ _ _ e.
  • 9. What materials would be suitable for the
    following items
  • A. Soldering iron bit.
  • B. Electric cables.
  • C. Hinges for indoor use.
  • D. Hinges for out door use.
  • 10. Name one ferrous alloy?

107
Homework Sheet 13. Drilling.
  • Draw the diagram and name the parts.

108
Homework Sheet 14. Drilling.
  1. List five safety precautions associated with the
    drilling machine?
  2. How are pieces held safely in the machine vice?
  3. What is the purpose of the slots in the table?
  4. When drilling what is the purpose of the puc.
    mark?
  5. What is the depth gauge used for?
  6. The table can be raised and lowered why is this
    necessary?
  7. How can very large pieces be held for drilling?
  8. State the two circumstances when the pupils
    should not use the drilling machine?

109
Homework Sheet 15. Drilling.
  1. List five different types of hole?
  2. Sketch each type of hole above?
  3. When drilling a hole of a very large diameter
    hole explain how you would do it?
  4. How can the size of a drill bit be checked
    quickly?
  5. Sketch this tool?
  6. What are the two types of drill bit available?
  7. Sketch each type of drill bit and say where they
    are used?
  8. What is a reamer? explain your answer with a
    sketch.
  9. Why is it necessary to ream a hole after
    drilling?
  10. What is the benefit of using a cutting fluid when
    drilling?

110
Homework Sheet 16. The Centre Lathe
  • Draw the diagram and name the parts.

111
Homework Sheet 17. The Centre Lathe
  1. What is the purpose of the headstock?
  2. What is the lathe bed?
  3. What is it made from and why?
  4. The slideways are machined into the lathe bed,
    what are they for?
  5. The tailstock is mainly used for what?
  6. The carriage is made up of three parts, what are
    they?
  7. State the purpose of each of the parts above?
  8. What is the top slide, what is it used for?
  9. The toolpost is used for what?
  10. The spindle is hollow, why is this?

112
Homework Sheet 18. The Centre Lathe
  1. Name the two types of chuck?
  2. What is the purpose of each type of chuck?
  3. Why should the chuck guard never be left open
    when the machine is running?
  4. Why should no more than one person operate the
    machine?
  5. In an emergency how can the machine be stopped
    quickly?
  6. Name the three ways of stopping the lathe?
  7. What direction should the spindle turn?
  8. What is the purpose of the automatic feed?

113
Homework Sheet 19. The Centre Lathe
  1. With the aid of sketch explain facing off?
  2. With the aid of a diagram explain Sliding or
    parallel turning?
  3. What is taper turning?
  4. How is taper turning carried out on the lathe?
  5. How are holes drilled on the lathe, use a diagram
    to explain your answer?
  6. How are finished pieces cut off from the rest of
    the material on the lathe?
  7. What other operation can be performed using the
    above tool.
  8. Sometimes it is necessary to have grip on a part
    how can this be carried out?
  9. It is not always possible to get a drill to
    produce a hole to the size required how else can
    this be done?
  10. How is a good surface finish achieved on the
    lathe?

114
Homework Sheet 20. The Centre Lathe
  • Calculate the spindle speed for each of the
    following tasks.
  • A 25mm brass bar with a cutting speed of
    540m/min is to be turned. With ? 3 calculate he
    spindle speed.
  • A 30mm mild steel bar is to be turned, the
    cutting speed is 30m/min. calculate the spindle
    speed.
  • A 50 mm aluminum bar with a cutting speed of
    100m/min is to be turned calculate the spindle
    speed.
  • A high carbon steel bar with a cutting speed of
    15m/min and a diameter of 30mm has to be turned,
    calculate a suitable spindle.

115
Homework Sheet 21. Mechanical Joining.
  1. Name four different types of rivet head?
  2. Sketch the four types of rivet?
  3. What type of joint do rivets produce?
  4. What are pop rivets used for?
  5. Sketch a pop rivet and say how it works?
  6. Sketch a pop riveter that you have seen.

116
Homework Sheet 22. Mechanical Joining.
  1. What is the job of a tap?
  2. Name three different types of tap?
  3. Sketch a taper tap and a tap wrench.
  4. When cutting threads M6 what size hole would be
    drilled 5 or 6mm, explain your answer?
  5. In threading what does the m stand for?
  6. What conditions would lead to a tap breaking in
    the hole?
  7. Describe all the stages in tapping a hole.

117
Homework Sheet 23. Mechanical Joining.
  • What tools are used to cut external threads?
  • Sketch a split die and name the parts?
  • Sketch a stock for holding split dies and name
    the parts?
  • When cutting threads of m5 on a bar what diameter
    should the bar be?
  • Name four different types of thread?
  • Which thread do we use most in the metalwork
    room?
  • Sketch the four different thread types and give
    a use for each?
  • What conditions could cause poor threads when
    cutting external threads?
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