The document discusses various material properties including tensile strength, hardness, malleability, ductility, and brittleness. It then covers the classification of materials into ferrous materials like cast iron and various grades of steel, non-ferrous materials such as aluminum, copper, brass, tin, lead, and zinc, and non-metallic materials. For each material, the document outlines typical properties and common applications.

1. Workshop Processes
Engineering Materials
1

2. PROPERTIES OF MATERIALS
What do you think the phrase
“a materials properties”
means?
“A MATERIALS INDIVIDUAL CHARACTERISTICS”
2

3. MATERIAL PROPERTIES
 Mechanical
Properties
 Electromagnetic
Properties
 Chemical and
Durability Properties
 Classification of
Materials
 Ferrous Materials
 Non Ferrous
Materials
 Non Metallic
 Thermoplastics
 Thermosetting
Plastics
 Organic Materials
 Smart Materials
 Symbols/Abbreviation
s
 Forms of Supply
 Identification Coding
3

4. This is the property of a metal, which
enables the work to withstand a
stretching load without breaking
4
TENSILE STRENGTH

5. The ultimate Tensile Strength (UTS) of
a material is the maximum load that
each unit of a cross sectional area can
carry before it fails. We call this the
tensile stress at failure.
5
TENSILE STRENGTH

6. This is greatly defined as the ability of a
metal to resist indentation or abrasion.
The measurement of hardness is
usually based on a metals resistance to
the indentation of either a hardened
steel ball or a diamond.
6
HARDNESS

7. MALLEABILITY
A material is considered Malleable
when it can be easily pressed or forged
into shape. Most metals have a greater
malleability when worked in the hot
condition. Rivets used in engineering
have to be Malleable so that they can
be formed.
7

8. DUCTILE
This term implies that a metal has the
ability to be drawn into rod or wire. The
ductility of a metal is determined by the
amount it will stretch lengthways before
it becomes brittle and fails. Because
ductility reduces as the temperature of
the metal is increased, metals are
usually drawn in the cold state.
8

9. BRITTLENESS
This is the opposite of plasticity. It refers
to the tendency of metal to break
suddenly when under load without any
prior warnings. Many metals in their
cast state will fracture when subjected
to a large enough impact. In some
metals an increase in temperature can
reduce brittleness, while in others it can
be caused to occur.
9

10. This is the ability of a metal to withstand
loads, which are not in the same line of
force.
10
SHEAR STRENGTH

11. COMPRESSIVE STRENGTH
This is the property that enables a
metal to withstand compressive loading
without fracture
11

12. PLASTICITY
This measures the ability of a metal to
be formed into a given shape without
fracture. As very few metals are plastic
in cold form state heat is used in most
cases to increase plasticity
12

13. ELECTRICAL CONDUCTIVITY
This is the ease with which a material
conducts electricity. The most common
material used for this is copper. Copper
has a high electrical conductivity which
allows current to flow, it is also cheaper
than gold which also has a very high
EC.
13

14. This is the ability of a material to
withstand an electrical current. Plastics
have a very low EC and a high EI which
will not allow a current to flow. This is
why plastics can be used as a good
insulator
14
ELECTRICAL INSULATION

15. FERROMAGNETISM
Any metal that contains large amounts
of Iron, Nickel or Colbalt can be made
magnetic. Metals that contain these
elements can be made to make
permanent and electromagnets
15

16. If you heat a magnet to approximately
800°C the metals magnetism will
disappear. This point is known as the
CURIE TEMPERATURE Of the material
16
FERROMAGNETISM

17. This is the ability of a material to resist
chemical attack
17
CORROSION RESISTANCE

18. SOLVENT RESISTANCE
Some rubbers and plastics are attacked
by certain chemicals. These chemicals
are called solvents. Materials that are
not effected by solvents are said to
have a High Solvent Resistence
18

19. If we are designing equipment that may
use Petrol, Diesel or certain lubricating
oils in its operation. We have to ensure
that we chose materials that may
contact these substances that have a
HIGH SOLVENT RESISTANCE
19
SOLVENT RESISTANCE

20. ENVIRONMENTAL
DEGRADATION
If we leave certain materials out in the
elements they will degrade.
20

21. Wood will rot if exposed to moisture.
Some plastics will turn brittle if exposed
to UV light. Certain Rubbers will also
degrade when exposed to UV light.
We can overcome this by choosing the
correct materials or protecting the
materials we select for various
applications
21
ENVIRONMENTAL
DEGRADATION

22. We can protect wood by painting or
varnishing it before use.
If we are using plastic for guttering, we
could use one colored black as black
plastic tends to stay more flexible for
longer.
22
ENVIRONMENTAL
DEGRADATION

23. If the application requires metals to be
used we can protect them from
corrosion by using jointing compounds
between mating surfaces, or we could
clad the metal in another metal so that it
acts as a barrier (Galvanized Zinc
Plating). Or we could just simply paint
the surface of the metal
23
ENVIRONMENTAL
DEGRADATION

24. WEAR RESISTANCE
As we know hardness is a property of
Wear Resistance. However Wear
Resistance can also be looked at as the
durability of the property. Machine
components that come into contact with
each other need to have high Wear
Resistance.
24

25. WEAR RESISTANCE
Examples of components that require
high Wear Resistance are:
 Bearing Surfaces
 Gear Teeth
 Sealing/Forming plates
 Guillotine Blades
25

26. CLASSIFICATION OF
MATERIALS
Materials used in engineering are divided into 3
main groups
These groups depend upon the properties which
the materials have.
The 3 classifications are:
Ferrous materials
Non-ferrous materials
Non-metallic materials
26

27. Iron is the main constituent of
FERROUS MATERIALS. They are
called Ferrous as the Latin for iron is
“Ferrum”
In its purest form Iron is a soft grey
metal that has poor casting properties
when molten and it will not give a good
surface finish when machined.
27
FERROUS MATERIALS

28. To overcome this and improve its properties we add
small amounts of Carbon, this also gives us a wide
range of Cast Irons and Steels
Examples are:
Cast iron
Low carbon steel
Medium carbon steel
High carbon steel
Alloy steel (stainless steel, high speed steel)
28
FERROUS MATERIALS

29. Cast iron contains between 2-4% carbon
This means that it can be poured into complicated
shapes easily when molten
The Carbon in Cast Iron is in the form of Graphite,
this Graphite also makes the material easier to
machine, when 2 pieces of Cast Iron rub together
this Graphite acts as a lubricant. Because of this we
can say that Cast Iron is self lubricating
Cast contains large voids in its make-up which adds
to its brittleness (excess carbon)
29
CAST IRON

30. Cast Iron does have a disadvantage,
unless it is specially treated
(ANNEALED developed in France in
the 18th century) to make it more
malleable. It is brittle and therefore
should not be subjected to high tensile
loading. It is however good at
withstanding compressive loading
30
CAST IRON

31. It is made by reducing iron ore in a blast
furnace. The liquid iron is cast, or
poured and hardened, into crude ingots
called pigs, and the pigs are
subsequently re-melted along with
scrap and alloying elements in cupola
furnaces and recast into molds for
producing a variety of products.
31
CAST IRON

32.  Examples of uses are:
 Machine Beds
 Surface Tables/Angle Plates
 Extreme compression components
 Housings
 Crank Shafts/Cases
 Frames
35
CAST IRON

33. STEEL
Steel is one of the most common ferrous
metals
It is available in many different forms and
can be ordered in two different forms:
Black
or
Bright
Steel is dull grey in appearance until
machined or treated
36

34. Black Steel
Black steel is the cheaper of the two
It has a black scaly surface that needs
to be machined
Bright Steel
Bright steel is more expensive
It is possible to leave the outer surface
un-machined
37
STEEL

35. PLAIN CARBON-STEEL
There are 3 main different varieties of
steel and they are determined by the
amount of iron and carbon present in
each. They are:
Low-carbon steel
Medium-carbon steel
High-carbon steel
By adding different amounts of carbon
to steel we can change its properties
they are then called Plain Carbon-steel
38

36. LOW CARBON STEEL
More commonly known as “mild steel”
It contains between 0.1% - 0.3% carbon
It has good Tensile Strength
It has a fair degree of malleability and ductility
when cold worked
When heated to a bright red colour (1490°F
810°C it becomes more malleable and ductile
which means it can be pressed or rolled
easily into shape
It is cheap which makes it deal for low level
engineering 40

37.  Mild Steel is one of the most widely
used materials in engineering.
Examples of its uses are:
 Girders
 Ships Hulls
 Gates and Railings
 Pipes
 General Workshop purposes
41
LOW CARBON STEEL

38. Contains between 0.3% - 0.8% carbon
Tougher and stronger than low-carbon steel,
making them hard to cut or form
The higher carbon content means that it can
be heat treated (using hardening and
tempering) to gain improved properties
This make them more expensive
They are difficult to work in a cold state and
could crack.
42
MEDIUM CARBON STEEL

39.  Properties:
 Strong
 Can be hardened by heat treatment.
43
MEDIUM CARBON STEEL

40.  Examples of use are:
 Hammers
 Chisels
 Punches
 Gears/Couplings
 Components that require a high degree
of wear and impact resistance.
44
MEDIUM CARBON STEEL

41. HIGH CARBON STEEL
High-carbon steels are the hardest steels
and the most expensive to produce but they
are less ductile
Contains between 0.8% - 1.4% carbon
They respond well to heat treatment.
Very poor at cold working and fracture easily
in this state
45

42.  Properties:
 Strong
 Can be made very hard by heat
treatment
46
HIGH CARBON STEEL

43.  Examples of use are:
Wood Cutting Chisels
Files
Taps and Dies
Craft Knives
47
HIGH CARBON STEEL

44. STAINLESS STEEL
In addition to the iron and carbon in
steels, Stainless Steel has Chromium
and Nickel in its make-up. It is part of
the Ferrous Metal groups called ALLOY
STEELS. The extra added constituents
mean that Stainless Steel is more
corrosion resistant than other Steels
48

45.  Properties:
 Corrosion Resistant.
 Strong
49
STAINLESS STEEL

46. Examples of use are:
 Food Preparation Counters
 Medical Applications
 Pharmaceutical Applications
 Cutlery
 Automotive Trim
50
STAINLESS STEEL

47. NON-FERROUS MATERIALS
Non-Ferrous materials DO NOT CONTAIN IRON
Examples are:
Aluminium
Copper
Brass
Tin
51

48. ALUMINIUM
Aluminium is the most common non-ferrous
material.
Aluminium is light grey in appearance,
unless it has been treated or made into an
alloy, silvery when polished.
52

49. Properties:
Light weight
Good conductivity
Corrosion resistance
Malleable
High weight to strength ratio
In its natural state is weak and ductile
53
ALUMINIUM

50.  Examples of uses are:
 Cylinder Heads
 Small Machine parts
 Tools
 Utensils
 Castings/Housings
54
ALUMINIUM

51.  Copper Aluminum Alloy with only a 5-
10% Aluminum content.
 Strong
 Fluid when molten
55
ALUMINIUM BRONZE

52.  Examples of uses are:
 Boiler and Condenser components in
heating systems
 Chemical plant componnets
 Boat Propellers
56
ALUMINIUM BRONZE

53.  As Aluminum use has grown there has
been a wide range of Aluminum Alloys
developed. By adding small amounts
Silicon, Copper, Magnesium and
Manganese you can greatly increase
the strength of Aluminum. Within
Aviation the most widley used
Aluminum Alloy is DURALUMIN. This
4% Copper and 1% Magnesium added
to it
57
ALUMINIUM ALLOYS

54.  Properties:
 Ductile
 Malleable
 Good Strength
 Good Fluidity when molten
58
ALUMINIUM ALLOYS

55.  Examples of uses:
 Electrical powerlines
 Ladders
 Aircraft and Motor Vehicle components
 Light sand and Die Casting
59
ALUMINIUM ALLOYS

56. LEAD
 Lead is a heavy grey metal that is very
malleable, it has a low tensile strength
but it is highly resistant to corrosion and
chemical attack. It conducts both heat
and electricity with ease.
 When mixed with Tin it produces a
range of alloys known as SOFT
SOLDERS
60

57.  Properties:
 Extremely soft.
 Heavy
 Low tensile strength
 Highly resistant to corrosion
 Malleable
61
LEAD

58.  Examples of uses are:
 Roofing.
 Chemical Tank liners.
 Balance Weights.
 Jointing Compounds for electrical joints.
62
LEAD

59. COPPER
Copper has excellent conductivity
Lightweight & very malleable
Corrosion Resistant
Excellent conductor of heat and electricity
Average Tensile Strength (this can be improved
by alloying with other metals)
Copper is the main ingredient in many alloys, such
as brass
In its natural state it is orangey-red appearance
Polishes well and easily joined
More costly than Aluminium.
63

60.  Examples of use are:
 Cooking Utensils
 Water Pipes
 Electric Cables/Wires.
64
COPPER

61. TIN
 Tin is soft and malleable
 Highly corrosion resistant
65

62.  Examples of use are:
 Tin Cans
 Protective coating for Mild Steel this is
known as TINPLATE
 Used in the production of some solders
 Used with Copper to produce Bronzes
66
TIN

63. ZINC
 Zinc is a soft brittle metal
 It is highly corrosion resistant.
 When used to “coat” other metals it has
a feathery appearance
67

64. ZINC
 Examples of uses are:
 Acting as a protective coating for Mild
Steel (this is then said to be
Galvanized)
 Building Materials
 Buckets/Waste Bins
68

65. STANDARD BRASS
Standard Brass is made up of 65% copper & 35% Zinc
Cheaper than most other brass alloys
Standard brass is gold/yellow in appearance
The High Copper content means that Brass is very
Ductile
The High Zinc content means that it is more fluid when
molten making it suitable for casting
It is only possible to harden brass alloy through cold
working (work hardening).
Heating softens the brass (the annealing processes) 69

66.  Examples of uses:
 Tubes
 Cartridge Cases
 Castings
70
STANDARD BRASS

67.  Bronze is an alloy of Copper an Tin the
amounts of each vary from 96% Copper
and 4% Tin to 78% Copper to 22% Tin
 The high Copper content means that it
is malleable, ductile and elastic when
forming when cold.
 The high Tin content means that it is
more fluid when molten allowing it to
pour easily
71
BRONZE

68.  Examples of uses are:
 High Copper content
Electrical contacts
Instrument Parts
 High Tin content
Pump and Valve components
72
BRONZE

69. NON-METALLIC MATERIALS
Non-Metallic materials contain NO METALS
Examples are:
Wood
Thermosetting plastics
Thermoplastics
Rubber
Ceramics
Glass
73

70. PLASTICS
There are many different types available.
They all fall into 1 of 2 different categories
Thermosetting plastics
Thermoplastics
74

71. THERMOPLASTICS
Thermoplastics do not undergo a chemical
change when heated, this means they can be
reheated and re-softened over and over again
These plastics are not as hard as thermosetting
plastics but they do resist impact better and are
tougher
Used for tubing, film, cable insulation
75

72.  Polychloroethene AKA Poly Vinyl
Chloride (PVC).
 PVC is a very good material, It can be
made hard or soft and it can be used in
a variety of ways dependent on its
application.
76
THERMOPLASTICS

73.  PVC
 This material can be made solvent
resistant for use in manufacturing
 When made hard and tough it can be
used in the manufacture of window
frames, guttering and drain pipes
77
THERMOPLASTICS

74.  PVC
 When soft it will age harden over time.
Used as cable and wire insulation, or as
upholstery. Both types can be coloured
to suit the use they are intended for.
78
THERMOPLASTICS

75.  Polyamide (AKA Nylon)
 Nylon has a multitude of uses. It is a
tough strong flexible material that is
solvent resistant. The downside to this
material is that is absorbs water and it
will deteriorate when exposed to the
elements
79
THERMOPLASTICS

76.  Examples of uses are:
 Bearings
 Gears
 Cams
 Brush Bristles
 Textiles
80
THERMOPLASTICS

77.  Methyl-2 methylpropenoate (AKA
Perspex)
 A strong rigid transparent material that
is easily scratched, a material that is not
resistant to petrol based solvent attack.
Perspex can be easily softened and
moulded into complex forms
81
THERMOPLASTICS

78.  Examples of uses are:
 Aircraft Canopies
 Aircraft transparencies
 Lenses
 Corrugated Roofing lights
 Machine guards
82
THERMOPLASTICS

79.  Polytetroflouroethane (AKA PTFE or
Teflon)
This material has a very smooth surface
with a low coefficient of friction which
means it is excellent bearing material.
83
THERMOPLASTICS

80.  Properties of PTFE Teflon.
 Tough
 Flexible
 Heat Resistant
 Solvent Resistant
 Low coefficient of friction
84
THERMOPLASTICS

81.  Examples of uses are:
 Bearings
 Seals and Gaskets in hydraulic systems
 Tape
 Non stick coatings
85
THERMOPLASTICS

82.  Thermosetting plastics or thermo-sets
as they are sometimes known start life
as either a liquid OR a powder. They
sometimes have fillers added to the
mixture to improve the mechanical
properties of the material. They are
molded into shape using heat and
pressure. It is whilst this process is
happening that they undergo a
chemical change.
86
THERMOSETTING PLASTICS

83.  The polymers within the material
become cross-linked together once they
are formed they cannot be broken.
 This means that once we have shaped
the Thermo-set we cann6t change it
87
THERMOSETTING PLASTICS

84. THERMOSETTING PLASTICS
Thermosetting plastics do undergo a
chemical change when they are
heated, and once this change takes
place the plastic can never again be
softened.
This means thermosetting plastics
tend to be hard and brittle
88

85. They are used mainly when heat is
going to be present during operation.
Mainly used in resin base (Epoxy
Resins) plastics like glass enforced
plastic (fibre-glass), and for mouldings
89
THERMOSETTING PLASTICS

86.  Phenolic Resin (AKA Bakelite)
 Not that commonly used anymore this
was one of the first Thermo-sets. It has
limited decorative value as its colors are
limited to either brown or black
90
THERMOSETTING PLASTICS

87.  Properties of Bakelite:
 Hard
 Solvent resistant
 Good electrical insulator
 Machinable
91
THERMOSETTING PLASTICS

88.  Examples of uses are:
 Electrical fittings
 Electrical components
 Insulated handles
 Old radio outercases
92
THERMOSETTING PLASTICS

89.  Urea methanol resin (AKA Formica)
 This is very similar to Bakelite however
it is naturally transparent
93
THERMOSETTING PLASTICS

90.  Properties of Formica are:
 Can be coloured
 Hard
 Solvent resistant
 Good electrical insulator
94
THERMOSETTING PLASTICS

91.  Examples of uses of Formica are:
 Electrical fittings
 Kitchen fittings
 Bathroom fittings
 Kitchen hardware
 Laminates
95
THERMOSETTING PLASTICS

92.  Methanal- Melamine resin (AKA
Melamine)
 Again this material has similar
properties to both Bakelite and Formica,
however when moulded this material
has a smooth finish
96
THERMOSETTING PLASTICS

93.  Properties of Melamine
 Harder than both Bakelite and Formica
 More heat resistant than both Bakelite
and Formica
 Can be moulded and machined
97
THERMOSETTING PLASTICS

94.  Examples of uses are:
 Electrical equipment
 Tableware
 Control knobs
 Handles
 Laminates
98
THERMOSETTING PLASTICS

95. EPOXY RESIN
 Epoxy resins come in a variety of forms
(SYSTEMS) and are made of:-
 • EPOXY RESIN
 • HARDENER
 They can cure rapidly or slowly,
permitting the selection of any form
designed for an application. Depending
on the epoxy selected, cure can be
achieved at any temperature range
from 5°C to over 200°C. Epoxy resin
systems 99

96.  They can be poured into moulds or
applied to Glass Fibre, Carbon Fiber or
Kevlar Fiber matting in /on moulds.
100
EPOXY RESIN

97. GLASS FIBRE
 Glass Fibre Reinforced Plastic (GFRP)
has a much higher elasticity than
metals, GFRP was only used
structurally where this characteristic
was beneficial, or of little consequence.
101

98.  Examples of uses for GFRP are:
Radomes and aerials (as a result of its
Radar transparency)
 Helicopter rotor blades
 Skin of honeycomb structure where
stiffness is either unimportant or
imparted sub-structurally.
102
GLASS FIBRE

99. CARBON FIBRE
 Carbon fibre is produced by a special
burning process. The result of this
process are fibres which are 8 to 10
microns in diameter, (a human hair is
60 microns in diameter,).
103

100.  Carbon, whilst possessing enormous
tensile strength along the length of the
fibre are relatively easily damaged in
shear. They are formed into a ‘tow’
(twist free bundle fibres). And a size
(epoxy based coating) is applied.
104
CARBON FIBRE

101.  This protects the fibres and also helps
bonding to the relevant resin system at
a later stage.
 The tows can also be woven into
matting's making them easier to handle
and work with, the resin system being
added later (after mixing) in a messy
process known as wet lay-up.
105
CARBON FIBRE

102.  In addition to conventional dry fibres,
carbon can be supplied in a form known
as “pre-preg”. In this condition the
manufacturer has already added the
resin system. The advantages are that
health and safety risks are lower, in so
far as no resin mixing is required (fume
extraction etc.)
106
CARBON FIBRE

103.  Disadvantages are that specialist
storage facilities are required to prolong
the life of the pre-preg (typically 30 days
at 20° C; up to 1 year at -18° C.).
107
CARBON FIBRE

104.  When carbon fibre is used as a repair
medium for metallic structures, galvanic
corrosion can be a problem. Scrim
cloths, adhesive films and Ballatine
balls are the common barrier methods
of alleviating this problem.
108
CARBON FIBRE

105. CARBON FIBRE
 Properties of Carbon Fibre are:
 High strength
 High stiffness
 Low density
 Good fatigue
 Good vibration resistance
 X-ray transparency an
 Chemical inertness
 Brittle 109

106.  Examples of uses of Carbon Fibre are:
 Aircraft Wings
 Aircraft Structures
 Formula 1 Nosecones/Rear Wings
110
CARBON FIBRE

107.  Kevlar is a yellow coloured Aramid fibre
(an organic polymer). The structural
grade Kevlar fibre, Kevlar 49, is
characterized by excellent tensile
strength and toughness but significantly
inferior compressive strength compared
to carbon.
111
KEVLAR

108.  The stiffness, density and cost of Kevlar
are all lower than carbon; hence Kevlar
may be found in many secondary
structures as a hybrid with fibreglass.
112
KEVLAR

109.  Advantages of Kevlar
 The primary reason Kevlar is becoming
widespread in the aircraft industry is the
materials excellent impact resistance.
Although damage will occur under
impact, it is localised and will not
spread, unlike laminates of carbon or
glass.
113
KEVLAR

110.  The result of an impact test in which a
panel of glass fibre and a panel of
Kevlar of equal stiffness were
repeatedly hit to a load of 907kg, using
a hemispherical rod, were as follows:
 5 ply GFRP failed after 836 hits
5 ply Kevlar survived 10,000 hits
with only minor damage
114
KEVLAR

111. 115
KEVLAR
 A Kevlar composite will fail via a ‘NON-CATASTROPHIC
YIELDING
MECHANISM’, (similar to metal), rather
than the fracture mechanism typical of
glass or carbon composites. When
impacted, Kevlar has an initial elastic
phase, where the material stretches to
absorb the “impact energy” rather than
fracturing of the structure as occurs in
carbon and glass.

112.  This ability of Kevlar to withstand impact
and continuous static loads results in
excellent fatigue resistance.
116
KEVLAR

113.  Examples of uses for Kevlar are:
 Aircraft applications. Ranging from
interior mouldings, wing and body
fairings, access panels, leading and
trailing edges, landing gear doors,
instrument panels and radomes,
propellers, cargo bay liners and
containers, engine noise absorption
pads and engine blade containment
rings.
117
KEVLAR

114.  Properties of Kevlar are:
 fibres can deteriorate under ultra-violet
light.
 Excellent fatigue resistance.
 Impact resistant.
 Energy absorbent.
 Poor compressive strength.
 Good Tensile Strength
118
KEVLAR

115. ORGANIC MATERIALS
 When using the term Organic Materials
we are referring to materials that have
come from nature. Such as:
 Leather
 Sinew
 Bone
 Timber
119

116. HARDWOODS
 We get our hardwoods from broad
leafed trees. The term hardwood can be
misleading. It does not mean that they
are “harder” than softwoods but
because of their relatively short fibres
they tend to be denser than softwoods
120

117. Hardwood Density
(kg/m³)
Moisture
content %
Uses
Elm 550 12 Lock Gates Piles
Outdoor
Cladding
Oak 720 12 Ship Building
House Building
Furniture
Mahogany 720 12 Furniture
Ash 810 12 Vehicle Bodies
Tool Handles
Teak 900 11 Indoor/Outdoor
Furniture
121
HARDWOODS

118. SOFTWOODS
 About 80% of the wood used today is
Softwood. It comes from quick growing
trees with long spikey leaves such as
conifers. These woods tend to have
long fibres making them less dense
than hardwoods
122

119. 123
Softwood Density
(kg/m³)
Moisture
content %
Uses
Spruce 420 13 General
Construction
work Boxes
Cases
Scots Pine 510 12 General
Construction
work Furniture
Flooring
Douglas Fir 530 12 Heavy
Construction
work Plywood
Larch 810 12 Outdoor
Purposes Mining
General
Purposes
SOFTWOODS

120.  These composites fall into 3 catorgries
Laminated Boards
 Particle Boards
 Fibre Boards
124
WOOD COMPOSITES

121. WOOD COMPOSITES
 Plywood is the most commonly known
Laminated Board. It consists of thin
layers of wood bonded together. To
prevent warping and to give strength
these boards are layered in such a way
that their grains run 90° to each other.
125

122.  Particle Board is made from recycled
materials such as sawdust or shavings
that have been bonded together to form
Chip Board. This Chip Board is used in
the manufacturer of Kitchen Units
126
WOOD COMPOSITES

123.  Fibre Board is made from compressed
fibres of differing length that have been
bonded together. They include both
Hardboards and Medium Density
Fibreboard (MDF)
127
WOOD COMPOSITES

124. WHAT ARE SMART MATERIALS?
128

125. SMART MATERIALS
 Smart materials are materials that CAN
undergo a change to their properties
WHEN there is a change to its working
environment
129

126. SMART MATERIALS
 What Smart Materials do you know of in
common everyday use?
130

127.  Piezoelectric Materials
 When you apply a force to certain
materials such as quartz you are
causing a potential difference to be set
up across the faces of the material at
90° to the force. This effect is known as
the PIEZOELECTRIC EFFECT
131
SMART MATERIALS

128.  This effect is used in pressure sensors
on sealing machines used in
pharmaceutical manufacture, vibration
recorders used on Health Usage
Monitoring Systems and microphones
132
SMART MATERIALS

129.  We can also use this effect in reverse if
we apply a voltage. This produces a
stress in the material which can cause it
to twist or indeed bend by a controlled
amount. Aircraft manufactures are
using these smart materials in the
manufacture of new aircraft.
133
SMART MATERIALS

130.  SHAPE MEMORY ALLOYS (AKA
MEMORY ALLOYS)
 When deformed these materials will
return to their original shape when
heated OR when the external force is
removed.
134
SMART MATERIALS

131.  These alloys contain special combinations of
Copper, Zinc, Nickel, Aluminium and
Titanium. They are used in medical
applications as VASCULAR STENTS that
are place in blocked or narrowing blood
vessels. They use your bodies temperature
to enlarge which opens the vessels
improving flow. They are also used in the
manufacture of Dental braces where the
bodies temperature causes them to contract
and exert pressure on the teeth
135
SMART MATERIALS

132.  MAGNETO-RHEOSTATIC FLUIDS
 Within these fluids are microscopic
magnetic particles that are suspended
in a type of oil. When we apply a
magnetic force these particle align
themselves along the magnetic flux
lines. This greatly restricts the flow of
the fluid. This can cause the fluids
viscosity to rapidly change from a fluid
to almost a solid
136
SMART MATERIALS

133.  These fluids have been used in fast
acting clutches, shock absorbers and
flow control systems.
137
SMART MATERIALS

134.  ELECTRO-RHEOSTATIC FLUIDS
 These are very similar to Magneto-
Rheostatic Fluids in that they will
become viscous in the presence of a
static electric field, again they line
themselves up with the flux lines which
opposes the flow of the fluid
138
SMART MATERIALS

135.  These liquids are extremely fast acting
and can change from a fluid to a stiff gel
and back again in milliseconds. They
are used in similar applications to
Magneto-Rheostatic Fluids
139
SMART MATERIALS

136. Material Recognition
Assessment
140

137. HOW ARE MATERIALS
IDENTIFIED
As engineers you will need to be able to
interpret the material requirements
given on engineering drawings, plans
and processes . This information is
often given in abbreviated form.
141

138. There may be occasions that you will
have to draw material from stores when
the storekeeper is not present for these
reasons you have to have an
understanding of how to identify
different materials used within
engineering.
142
HOW ARE MATERIALS
IDENTIFIED

139. The constituents of the different metals
and alloys in use are specified by the
British Standards Institution (BSI),they
will also state the most appropriate use
and operating conditions (especially
high temperatures/pressures) for the
material
143
IDENTIFICATION CODING

140.  There is also the European BS EN
10277 standards for steels
 Previous identification methods for
steels include:
 BS 970 issued in 1991
 BS 970 issued in 1955
144
IDENTIFICATION CODING

141. IDENTIFICATION CODING
Material BS EN
10277:1999
BS 970:1991 BS 970:1995
Mild Steel 1.7021 210M15 EN 23M
Medium Carbon
1.0511 080M40 EN 8
Steel
Tool Steel 1.3505 534A99 EN 31
Free Cutting Steel 1.0715 230M07 EN 1A
High Tensile Steel 1.0407/1.1148 605M36T EN 16T
145

142. Supplier Manufactures often have their
own coding systems, metal bars are
often painted on their ends so that they
can be easily identified at a glance,
some use tags that correlate to certain
information. Whatever system is used in
your work place YOU should familiarise
yourself with it.
146
IDENTIFICATION CODING

143. Material Colour Code
Mild Steel Red
Medium Carbon Steel Yellow
High Carbon Steel Purple/White
Free Cutting Steel Green
High Tensile Steel White
147
IDENTIFICATION CODING

144. 148

145.  Certificates of Conformity, (COCs) are
issued by the Manufacture of the
material and come in the form of a
certificate, A-4 size, which should be
attached to the material
149
IDENTIFICATION CODING

146.  The COC itself gives a range of
information of which some examples
are:
150
IDENTIFICATION CODING

147. IDENTIFICATION CODING
The Manufactures Name and address.
The Manufactures QA Stamp.
Dimensions and thickness of material.
Composition of material.
COC reference number.
Batch number.
Reference to which material conforms to,
usually in the form of material specification. 151

148. Batch Numbers are similar to use as serial
numbers of components but are no longer
stamped/etched or painted onto materials
such as sheet metals due to the fact that
the process of stamping such numbers
induces stress, and paint can easily be
erased in transit. Batch numbers are now
found on the COC.
152
IDENTIFICATION CODING

149. SYMBOLS AND
ABBREVIATIONS
The following is part of a typical title
block used on an engineering drawing,
containing the information on the
material to be used
153

150. TITLE BLOCK
154
Title
Connector
Scale 1:1
Projection
Drawn: FB
Date: 25.10.13
Checked: MJ
Date: 25.10.13
Material:
BDMS to
BS
070:040A.10

151.  The material specified in this example is
 BRIGHT DRAWN MILD STEEL BDMS
 The other information BS 070:040A.10
relates to it’s British Standards (BS)
specification. This specifies the % of
each of the ingredients of a material
and its recommended uses
155
TITLE BLOCK

152.  The drawing itself may also give you
some further information, such as the
surface finish, heat treatment, surface
hardness.
 For Bar Stock, Sheet or wire it may also
give you some dimensional information
156
TITLE BLOCK

153. ABBREVILE TABLE FOR
SOME COMMON METALS
Abbreviation Material
CI Cast Iron
SG Iron Spheroidal graphite Cast Iron
MS Mild Steel
BDMS Bright Drawn Mild Steel
CRMS Cold Rolled Mild Steel
SS Stainless Steel
Alum Aluminium
Dural Duralumin
Phos Bronze Phospher Bronze
157

154. Abbreviation/Symbol Interpretation
ISO International Organisation for
Standardisation
BS British Standard
BSI British Standard Institution
BH Brinell Hardness number
VPN Vickers pyramid hardness number
SWG Standard Wire Gauge
Ø 50 50 mm diameter
MS, Hex Hd Bolt-M8x1.25x50 Mild Steel Hexagonal headed,
metric bolt 8mm diameter,1,25mm
pitch,50mm long
158
ABBREVILE TABLE FOR
SOME COMMON METALS

155. MEANINGS
 Surface hardness is tested by pressing
some form of indenter into the surface
of the material and then using the
dimensions of the indentation to
calculate a hardness number
159

156.  Standard Wire Guage (SWG) is a
means of classifiying a wires diameter
or the thickness of sheet metal.
 The higher the number the thinner the
material.
160
MEANINGS

157. FORMS OF SUPPLY
How do engineering materials begin their
life?
161

158.  Metals begin their life as ores
 Plastics are derived from the by
products of oil distillation and from
vegetable sources.
 Timber is obtained from Forestry.
162
FORMS OF SUPPLY

159. The ores for metals are smelted or
otherwise extracted and produced into
ingots. These then go on to secondary
processing. This may occur at the same
site.
163
FORMS OF SUPPLY

160.  Plastics are converted into powders,
granules and resins
164
FORMS OF SUPPLY

161. Timber is transported to mills for cutting
and seasoning before use.
165
FORMS OF SUPPLY

162. Once all of the manufacturing
processes have been undertaken the
materials are stored ready to be
distributed to various engineering
companies and merchants for use
166
FORMS OF SUPPLY

163. METALS POLYMERS TIMBER
Ingots Powders Planks
Castings Granules Boards
Forgings Resins Composite Sheets
Pressings Sheet Rods
Bars Mouldings
Sheet Pipe/Tube
Plate Film
Pipe/Tube
Wire
Rolled Sections
Extrusions
167
FORMS OF SUPPLY