2. What is a fastener? A device to locate or hold parts
As a repair technician you will become skilled at removing, reconditioning, replacing, and installing fasteners.
An important skill to learn is how to remove a stuck fastener without breaking it off.
(You will get lots of practice with this as a technician)

4. How do you remove a stuck fastener?
An easy treatment for stuck nuts and bolts is Penetrating Oil (like WD-40).
Some brands work better than others, so ask what works and experiment on your own.
Spray it on the threads and shock or vibrate the fastener (hit it with a hammer) to get the oil to sink in.
You must allow time for oil to work into threads.
I spray and shock a stuck bolt, then go work on another job for an hour or so to let the magic happen

5. Remove a stuck fastener
Remove a stuck fastener? (After spraying with oil and waiting for it to soak in.)
Use a six point wrench or socket

6. Remove a stuck fastener
Remove a stuck fastener? (After spraying with oil and waiting for it to soak in.)
You might also use a breaker bar with a 6-point socket
Breaker bars are longer and stronger than ratchets
Never put a pipe on a ratchet handle to get more torque
It will damage the gears in the head of the ratchet

7. Remove a stuck fastener
Remove a stuck fastener? (After spraying with oil and waiting for it to soak in.)
Use a six point wrench or socket
Try to tighten slightly, then loosen
An impact can help shock the fastener loose
A strong impact will often break off the bolt

8. What about using Vice Grips to remove a stuck bolt?
Vice Grips (locking pliers) damage the head of a bolt or nut and make it MUCH more difficult to remove.
Use Vice Grips to hold or grip objects.
They should never be used as a wrench, or a socket.

9. How do you remove a stuck fastener?
Heat can help loosen a fastener
Too much heat can damage the fastener
Too much heat can weaken the surrounding metal
NEVER heat fasteners red hot

10. When do you use a new fastener?
If it is damaged in any way such as:
corrosion or stretched threads
Always replace Torque to Yield bolts

11. What is a torque to Yield Bolt?
Most commonly used for head bolts
They are tightened (torqued) until they just begin to stretch
This provides a very consistent clamping load and helps keep an even sealing pressure for the head gasket

12. This is how you identify torque-to-yield bolts

13. Torque to Yield bolts require special procedures
Tighten to the specified torque
Continue to turn the fastener just enough to cause it to begin to stretch
This will be specified in degrees of rotation

14. This tool is used so you can see exactly how many degrees you are turning a torque to yield bolt

15. What replacement fastener should you use?
Same Length
Same Diameter
Same Thread Pitch
Same Plating or Material
Same hardness or GRADE
Same weight

16. Bolt Length and Diameter

17. Thread Pitch is measured with a special gauge

18. The correct gauge will match the grooves of the bolt

19. This gauge has a the same thread pitch as the bolt

20. This gauge has a different thread pitch than the bolt

21. Same Pitch

22. Different Pitch

23. These gauges can measure the diameter, pitch and bolt length

24. What replacement fastener should you use?
Same Length
Same Diameter
Same Thread Pitch
Same Plating or Material
Same hardness or GRADE
Same weight

25. Always use the same plating or material as the original fastener
Nuts and Bolts are not all the same.
They must be compatible with the other metals they contact
Many have special plating to resist corrosion
The material or plating will change the general torque (or tightening) value.

28. What replacement fastener should you use?
Same Length
Same Diameter
Same Thread Pitch
Same Plating or Material
Same hardness or GRADE
Same weight

29. Bolt Grade Bolt Grade is important and easy to identify
A good article on this is at

30. Bolt Grade Both bolt heads marked A are the same grade
Both bolt heads marked B are the same grade
The top are SAE, the bottom are metric
Which bolts are stronger, A or B?

31. When do fasteners have to be the same weight?
Any time the nut or bolt is on a rotating part
Cooling fans
Drive pulleys
Flywheel or clutch or torque converter
Lug nuts Drive shafts

32. Rotating parts If you replace one fastener on a rotating part…
Replace them all to keep them the same weight
Failure to do this may cause vibration and an unhappy customer

34. How do fasteners lock in place?
Proper torque is usually the only thing that keeps a bolt or nut from vibrating loose
Sometimes lock washers are used, especially when a light fastening torque is desired
Over-tightening a lock washer will ruin it’s ability to hold
Do not any washers unless they were used by the manufacturer

35. How do fasteners lock in place?
Cotter pins, locking tabs, and self locking nuts are often used.
You should replace these with new ones to ensure they do not fail

36. How do fasteners lock in place?
Thread locking compounds are often used
Two types that are widely available are… Red LocTite© and Blue LocTite©
Use the BLUE unless specified. Using Red LocTite© will make a bolt almost impossible to remove after it the LocTite cures
It is O.K. to use Blue LocTite© for most applications

37. Do not re-use Cotter pins
Nuts in critical locations such as connecting rod nuts

38. Always use a NEW cotter pin

39. Use new fasteners in highly critical locations like this connecting rod

40. Inspect all self locking nuts
Some lock nuts are distorted at the top to create an interference fit.
These will wear out after being removed and installed several times

41. Inspect all self locking nuts
Some lock nuts use a nylon insert that may wear out if they are removed and installed too often

42. Inspect all self locking nuts
Self locking nuts should feel tight when the threads of the bolt reach the top of the nut.
If they spin on with little resistance you should replace them with new ones.

43. What do you put on threads?
Anti-seize compound will make it easier to disassemble nuts and bolts
Blue LocTite© will help keep nuts and bolts from vibrating loose
Be sure to clean threads before using LockTite