Tools, Fabrication and Measuring Devises Flashcards
Define malleability
The ability to be bent or reshaped without snapping back into the original shape
Define elasticity in terms of metal
The ability to be bent or reshaped but snap back into the original shape
Define toughness in terms of metal
The ability to resist being compressed under force
Define tensile
The amount of stretching/tension a metal can take without breaking
Define ductile
The ability to be bent or stretched without breaking
What is low carbon steel used for
Wheel rims, covers, screws, washers, bolts, nuts, fasteners
What is high carbon steel used for
Frames, chassis, bushings, door panels, support beams, mufflers
What is boron steel used for? Why?
Side impact bars
High strength but low weight
What are aluminium alloys used for
Cylinder heads and wheels
Give 2 advantages of brass
Corrosion resistance, electrical conductivity
Give 3 advantages of copper
Electrical conductivity, heat conductivity, softness
How is the front wind screen different to the glass in other windows of the car
The windscreen is tempered glass, the rest are laminated.
What did brake pads used to be made of? What are they now?
Asbestos, kevlar
What is the main type of saw we use?
Hacksaw
What is the main type of hammer we use
Ball peen hammer
What is the tool used to make threads in holes drilled into metal
Threading tap
What’s the name for a metal ruler?
Steel rule
What’s the tool used to remove broken bolts?
Stud remover
Why is the chance of an axle stand failing very low?
It’s completely mechanical and has a sturdy design
What are axle stands usually made of? What’s a slightly less common alternative?
Steel
Aluminium
How is a tubular type axle stand locked?
The steel pin enters both the hole in the stand and in the tube inside, locking them both in one place
How is an axle stand with a toothed section locked?
The steel handle is released and the toothed section is lowered
List 3 things to check are correct when jacking up a vehicle
Using an axle stand once the vehicle is at its desired height
Using correct jacking points
Checking the ground is level and firm
What do you do if unsure about the suitability of jacking points?
Consult the vehicle’s manual or handbook
What are the 2 basic categories for threaded fasteners?
Bolts, studs
List 2 characteristics of a bolt
The cylindrical part has a thread
One end has a head
Give 1 characteristic of a stud
One stud can have 2 ends with different threads
How do you determine the length of a bolt?
The full length of the bolt, head not included
How do you calculate the thread depth of a bolt or stud?
(outer diameter - inner diameter) / 2
What is the pitch of the bolt thread?
Number of threads per cm/inch
What is meant by a coarse pitch thread?
Less threads per cm/inch
What are clockwise threads referred to as?
Right-hand threads
Anti-clockwise threads are known as left-hand threads. Are right or left hand threads used most often?
Right-hand threads
Does a left-hand thread run bottom right to top left or bottom left to top right?
Bottom right to top left
What does UNC stand for? What does it mean?
Unified National Coarse
A coarse thread
What does UNF stand for? What does it mean?
Unified National Fine
A fine thread
What are the 2 main types of thread?
Imperial (inches) and metric (mm)
Are UNC and UNF measured in inches or mm?
Inches
In UNC sizes, what does 5/16-18 mean?
5/16 of an inch diameter
18 threads per inch pitch
According to metric measurements, what does M8 x 0.75 mean?
8mm diameter
0.75 thread per mm pitch
If in metric sizes, it only says M8, without the second part (e.g. x 0.75), what is the pitch assumed to be?
What about these:
M1, M2, M3, M4, M7, M10
1.25mm
0.25
0.4
0.5
0.7
1
1.5
List 3 factors the tensile strength of a bolt depends on
The material
The manufacturing method
The hardening process
According to the SAE norm, how can you find out the tensile strength of a bolt?
Count the number of marks on the bolt head. A higher number means a higher tensile strength.
According to the ISO norm, how can you find out the tensile strength of a bolt? What else can you find out?
Look at the numbers of the bolt head. The higher the number before the dot, the higher the tensile strength.
The number after the dot indicates the maximum elongation.
(e.g. 8.8)
Why are washers used? (2 reasons)
To prevent the bolted joint from coming loose
To prevent damaging the surfaces
List 4 types of washers
Star washer
Spring washer
Repair washer
Flat washer
Name 2 types of washers designed to lock a bolted joint
Star washer
Spring washer
How do star washers and spring washers lock onto bolted joints?
The flattening of the ring provides a pre-load
When are nuts used in a bolted joint?
When the object itself has no internal thread
List 6 types of nut
Flange nut
Normal nut
Crown nut
Oval flange nut
Cap nut
Nut with a nyloc ring
What is a self-locking nut? List 4 self-locking nuts.
A nut that will not come loose due to vibrations.
Crown nut
Castle nut
Oval flange nut
Nut with a nylon ring
Which type of locking nut requires an extra part to provide locking?
A crown nut
Which 2 methods are used in the metric system to show the strength of a nut?
A colour
A number
What did imperial nuts used to be marked with to indicate strength? What is used now?
Radial marks
A dot and dash
How can you tell the strength of a nut by a dot and a dash?
The closer together they are, the stronger the nut
What are spanners most commonly made out of?
The steel alloy Chromium-Vanadium
Give 2 reasons that spanners are heat-treated and chromium-plated
To enhance durability
To reduce fragility
Is a spanner that is too small or too big more likely to damage a bolt head.
An oversized spanner
Describe a ring spanner
A spanner with closed ends, like a ratchet but not rotating
Give 2 advantages of a ring spanner
2 different sizes at each end, so more versatile
A relatively large force can be transferred compared to fork spanners
Describe a fork spanner (3 points)
A spanner with open ends on both sides
Different sizes at each end
Spanner head is usually at a 15 degree angle
Why doesn’t a fork spanner transfer as much force as a ring spanner?
Only 2 contact faces
What’s the name for a spanner with a ring spanner on one end and a fork spanner on the other?
Combination spanner
What’s another name for an adjustable spanner?
A shifting spanner
What on the adjustable hammer is used to adjust it?
The spindle
What does a pipe spanner look like
Both sides look like a combination of a ring and fork spanner (a ring spanner that isn’t fully connected)
Why is a pipe spanner preferable when repairing a brake pipe?
More contact faces reduce the risk of slipping and damaging the bolt or nut, but a ring spanner wouldn’t be able to get onto it because the pipe would be in the way of the closed end
What’s the spanner with a fork spanner on one end and a ratchet on the other called?
A ratchet ring spanner
What does 1 N mean?
1 Newton
If a 1 N force is exerted on a 1 metre bar, what will the torque at the end of the bar be? So what is the calculation? Write it in 2 ways.
1 Nm (Newton metre)
Force x distance = torque
N x m = Nm
What does a torque wrench do?
Tightens nuts and bolts to a particular torque
In using a torque wrench, you turn the knob to set the torque to 95 Nm. How do you know when the nut/bolt you’re tightening is at 95 Nm?
It will click
Why do you have to loosen a torque wrench back to its lowest value
after use?
Otherwise, it will become inaccurate
What is the lowest measurement that can be made by a micrometer?
0.01mm
What is the lowest measurement that can be made by a steel rule?
0.5mm
What does DTI stand for?
Dial test indicator
What is the lowest measurement that can be made by a DTI?
0.01mm
What is the OHMS law calculation in letters? What do they mean?
V = IR
Voltage = current x resistance
What tool do you use to measure the gap of a spark plug?
Gap gauge/feeling gauge
What is the typical shelf life of a tyre?
5-6 years
State the 2 types of glass normally used on a motor vehicle
Tempered glass, laminated glass
In the calculation for OHMS law, what measurements are used for resistance, voltage and current?
Ohms
Volts
Amps
What type of hammer is used in conjunction with a Dolly block?
Long pick hammer
How many micrometres are there in a millimetre?
1000
List 6 components of a micrometer
Heat-insulated handle
Anvil
Measuring spindle
Barrel
Ratchet
Lock lever
Where do you hold the micrometre when you’re going to take a measurement? Why?
The heat insulated handle. The micrometre can expand due to the heat of your hand.
What 3 dimensions can you measure with a caliper?
Internal, external, depth
In which situations are pop rivets used? What kind of joint do they make?
To join 2 or more parts
A semi-permanent joint that can be separated fairly easily
Many modern engines have a cylinder head gasket which is made from:
Multiple layers of steel
Should metal files be stored together without protecting the teeth?
No
When carrying out fitting activities on a vehicle is it important to allow for temperature change when considering clearance and tolerances?
Yes
What are feeler gauges used to measure?
Gaps in metals
What is PTFE used as an electrical insulator for?
Cables
WHat drill size should be used when tapping an 8mm thread into a metal?
6.8mm
What do you do before using an ohmmeter?
Calibrating it
Is copper ductile and malleable?
Yes
When should you not remove the leads from a battery?
When it is being charged
At what temperature does steel go cherry red?
700 to 800 degrees celsius
Should you use ammeters across the terminals of batteries?
No
When cutting very hard thin metals with a hacksaw, what teeth does the saw require?
Wavy set with 32 teeth per inch
What metal does a ferrous metal contain a large proportion of?
Iron
What does it mean for a material to have high plasticity?
Can be permanently deformed without breaking
What’s the opposite of a threading tap?
A threading die
What 2 tools are used to clean and restore threads?
A thread file
Die nut
What’s the thing that looks like a compass but isn’t?
A divider
What on a car are alloy steels used for?
The most highly stressed components
Are steels ferrous?
Yes
Give one example of an aluminium alloy
Chromium
Define cast iron
Iron with 2% or more carbon
Give one synonym for tempered
Hardened
Describe the process of annealing. What is the effect on the material?
Heat a material above its recrystalisation temperature and maintain it there, then cool.
Increased ductility and toughness.
How is steel treated when it’s become too hard and not ductile enough? What is this process called?
It’s heated until it’s cherry red, then left to cool in the open air.
Normalising.
When is ceramic used on cars?
A wax-like coating
Name 3 parts of a car that can be made of kevlar
Brake pads, clutches, gaskets
Describe the properties of thermosetting plastics
Permanently hardened and fixed
Describe the properties of thermoplastics
Hardened and fixed while cool but malleable while hot
Why is the glass in the front windshield tempered rather than laminated?
So if it smashes, the driver can still see
Name the 2 types of rubber
Natural and synthetic
What does it mean to vulcanise rubber? What kind of rubber is it done to?
Add sulphur to improve elasticity and prevent perishing.
Natural rubber from tree sap.
How is tempered glass made?
Heating and cooling it rapidly using blowers
Give 2 potential issues that could come from over-tightening nuts and bolts
Elongation
Thread deformation
How do nyloc nuts prevent themselves from coming loose?
By squeezing the threads of the bolt as the nut is tightened
Give the name for each fit:
A fit with more than enough space
A fit with less than enough space
A fit in the middle
Clearance fit
Interference fit
Push fit
What do you do if a hydraulic jack is leaking?
Notify the supervisor
Name the 6 pronged star profile scredriver
Torx
What is the rivet with only one side access
Blind rivet
What tool is used to tap moulding into place?
RUbber mallet
Why is low carbon steel used on the bodywork?
Easy to mould into shape
What tool is often used in very confined spaces
Body spoon
What tool is often used with a beating file
Wooden mallet
ABS measures wheel speed using what?
Magnetic sensor
