Chapter 5 Hand tools and shop equipment Flashcards
What year did the metric system become the official measurement system in canada?
1970
The basic unit of imperial measurement is?
Inch
The basic unit of metric measurement is?
Metre
What are fasteners?
Things used to hold/secure parts of things together
What is the most common type of fastener in automotive?
Threaded
How are the threads created on a threaded fastener?
Cut or rolled
Which is better, cut or rolled threads?
Rolled threads are 30% stronger and have better fatigue resistance
What are the main types of thread?
Coarse and Fine
When do you use coarse threaded fasteners?
-General purpose work
-When rapid assembly/disassembly is required
When do you use fine threaded fasteners?
-When greater holding force is necessary
-When greater resistance to vibration is needed
Bolts defining characteristics?
-Head on one end, threads on the other
-Shoulder below the head (No threads)
-Threads do not travel from the head to the end
(interrupted by the shoulder)
How are bolts identified?
-Head size
-Shank diameter
-Thread pitch
-Length
-Grade
Cap Screws Characteristics
-Similiar to bolts
-No shoulder
Can you use a Cap Screw in place of a bolt
No
Stud defining characteristics
-Rods with threads on both ends.
How do studs work?
-One end of the stud is threaded into a threaded bore (hole)
-A hole in the part to be secured is fitted in place over the free end of the stud and held in place with a nut
Do the threads on a stud have to be the same on both ends?
-No, Studs often have a fine and coarse end
When are studs used?
-When the clamping pressures of fine thread are needed but a bolt wont work.
-When the material that the stud is being threaded into is soft or coarse the threads must be coarse
How is having fine thread on one end and coarse on the other helpful
-It allows you to have the clamping power of fine threads with the holding force of coarse
When are nuts used?
-When the threaded fastener is not threaded into a work
What is the most common type of nut?
-Hex nut
Why use lock nuts?
-When vibration my loosen a regular nut over time.
Types of lock nut
-Nuts with a nylon insert that cushions the vibrations
-Nuts that are distorted to provide resistance to thread movement
What are Setscrews?
-Screws used to prevent rotary movement between two parts
Setscrew Characteristics
-Either square headed
-Or headless (need to use an allen wrench or screwdriver to remove)
Machine screws characteristics
-Threaded from the head to the tip
-Have a head on one side and a flat tip on the other
-Round, flat, torx, oval, or fillister head
When are Machine screws used?
-Mount one piece to another with a threaded bore
-Can also be used with a nut to hold pieces together
What are self tapping screws?
-Screws that make their own threads into the material they are threaded into.
Is the size of the head and the size of the bolt are the same?
-No, It varies with the diameter of the bolt but it does not dictate the size of the bolt, just the size of the wrench
Bolt head uses
-Used to tighten and loosen bolts
-Wrenches and sockets fit over it
How is the size of a bolt determined?
-Diameter of its shank
What is bolt diameter?
-Measurement across the major diameter of the thread or the shank
What is Thread Pitch (Imperial)
-The number of threads per inch
What is Thread Pitch (Metric)
-The distance (in mm) between two adjacent threads
-Distance varies between 1.0 and 2.0 (lower is smaller)
What does tensile strength or grade refer to?
-The amount of stress or stretch that a bolt is able to withstand before it breaks
What determines a bolts grade?
-Type of material
-Diameter of bolt
How is the grade of a bolt indicated (Imperial)
-Number of radial lines on the bolts head
-More lines=Stronger
-Count the number of lines and add two to get the grade
-Id by the Society of Automotive Engineers (SAE)
What is Yield strength?
-How much stress a bot can take before it will no longer return back to its original shape without damage
How is the grade of a bolt indicated (Metric)
-Property class number on the bolt head
-1st number=Tensile strength
-2nd number=Yield Strength (Number is a % of the Tensile)
-Id by the International Organization for standardization (ISO)
How are nuts graded?
-To match with their respective bolts
-Imperial uses dots
-Metric uses numbers
What is a bolts fillet?
-Smooth curve where the shank meets the head
What is the most common type of break?
-Fatigue breaks
-Caused by the bolt being too loose and working back and forth
What happens when a bolt is tightened?
-The bolt will stretched and become “Spring loaded” against the part that it is holding
-Over tightening causes over stretching
How much is a properly tightend bolt normally streached?
-70% of its elastic limit
What is an elastic limit?
-The limit that the bolt will stretch and still be able to return to its original shape
Why are flat washers used?
-To spread out the load of tightening a nut or bolt
Why are compression and copper washers used?
-To spread the load and help seal one component to another
-Ex. Oil pan drain bolts
Why use anti seize Lubricant?
-To stop a bolt from becoming hard to removed over time.
-Ex.In an aluminum engine block
Why use thread sealants
-To prevent liquids from seeping past the threads
Why use thread lock?
-Prevent bolt from working loose over time
Define Hydrostatic Lock
-When a liquid is trapped in a blind hole, the bolt cannot compress the liquid so it cannot be properly tightened.
-Damage can occur, even a severe as a cracked block
Thread pitch gauge
-Tool used to provide a quick and accurate measurement of thread pitch
Hand Tap
-Tool used for hand cutting internal threads
Hand threading die
-Tool used to hand cut external threads
Threaded inserts
-Used when threads in a bore are excessively damaged
-Drill the hole out bigger and install an insert with the original threads
Why should you never pry, strike drop or force measuring tools?
-Doing so may cause damage as measuring tools are very delicate
What is a Machinists rule?
-Looks very much like an ordinary ruler but is much more precise
What is a Vernire Caliper
-A measuring tool that can make inside, outside and depth measurments.
Characteristics of all Vernier Calipers
-A moveable scale parallel to a fixed scale
-Has both metric and imperial options on the tool
Characteristics of the metric part of Vernier Calipers
-Main scale is divided into Cm which are divided by 10mm graduations
-The Vernier scale is divided into 50 equal divisions; each representing 0.02mm
Characteristics of Imperial part of Vernier Calipers
-Main scale is divided into inches which are divided into 10 equal parts of 0.100 of an inch
-The Vernier scale is divided into 25 equal divisions each representing 0.001 of an inch
How to read a Vernier caliper
-Combine the main and Vernier scale numbers
-Only one line on the vernier scale will line up with the main scale
What is a dial Caliper
-An easier to use version of a vernier caliper
-Available in metric or imperial
Characteristics of metric Dial Calipers
-Measure from 0-150mm (typically) in increments of 0.02mm
-Bar scale is divided into 2mm increments (one rotation of the dial indicator needle)
Characteristics of all Dial Calipers
-Depth scale
-Bar scale
-Inside measurement jaws
-Outside measurement Jaws
-Use a thumb operated roll nob for fine adjustments
-Accurate to 0.05mm or 0.002 of an inch
Characteristics of Imperial dial Calipers
-Main scale is divided into graduations of 1/10th (0.1) of an inch (one rotation of the dial indicator needle)
-The dial indicator is divided into graduations of one thousanths of an inch (0.001)
What is a Micrometer
-The preferred method when very precise measurements are desired
-Measures inside and outside linear dimensions
Characteristics of a Micrometer
-Parts include the frame, anvil, spindle, locknut, sleeve, sleeve numbers, sleeve longline, thimble marks, thimble and ratchet.
-Measure with accuracy up to 0.01mm or 0.001inch
What is a telescoping gauge also sometimes called?
-Also Known as a Snap Gauge
What is a telescoping gauge?
-A measuring tool used to measure bore diameters and other clearances
Telescoping gauge characteristics
-Consists of two telescoping plungers, a handle and a lock screw
-Availible in a verity of sizes normally ranging from approx 7mm(1/4inch) to 150mm(6inch)
What is a small hole gauge also known as?
-Also known as a Ball Gauge
Small hole gauge characteristics
-Works like a telescoping gauge but is ment to be used on small bores.
-Consists of a lock, handle, and expanding end
What is a feeler gauge
-A small strip of thin metal or plastic used to measure gaps/clearance
What is a dial indicator?
- A tools used to measure movment
Why use a flair nut wrench?
- They surround the nut more than an open-ended wrench
-Are less likely to round the nut, especially one made of a softer material like on brake line fittings
When do you use a crawfoot wrench adapter?
-Typically used when a hex fitting is used on a line or fitting that is in a restricted or shrouded area that prevents the use of a regular socket
Steps for an accurate reading with a torque wrench
- Locate the specs/procedures for a job
- Divide the torque spec into three
3.Hold the wrench so that it is 90degrees from the fastener being tightened
4.Tighten to 1/3 of the spec
5.Tighten to 2/3 of the spec - Tighten to within 11ftlbs of the spec
- Tighten to spec
8.Recheck
