Locking Devices

Question 1

What is the purpose of a locking device

Answer 1

Prevent loosening or disengagement of components under vibration, stress and temperature

Question 2

What are the classes of locking devices

Answer 2

1st class - No amount of vibration will loosen the thread
2nd class - Friction is the primary locking method

Question 3

What are examples of a 1st class locking device

Answer 3

Wire locking
Tab locking
Split pinning

Question 4

What are examples of 2nd class locking devices

Answer 4

Spring washers
Stiff nuts

Question 5

What types of locking washers are there

Answer 5

Spring
Shake proof
Tab
Serrated

Question 6

How does a locking plate work

Answer 6

Metal plate fitted over nut, screwed into component surface after installing

Question 7

What is peening

Answer 7

Locking threaded fasteners by deforming the thread of the bolt

Question 8

What is peening not to be used on

Answer 8

Titanium fasteners
High tensile steel fasteners
Set bolts

Question 9

How many threads are to be protruding before peening

Answer 9

1.5 - 2