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?