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