M6.5 Fastners Flashcards
How can you measure the screw pitch
By using a screw thread pitch gauge
What does class 1 mean
Loose fit
What does class 2 mean
Free fit
What does class 3 mean
Medium fit
What does class 4 mean
Close fit
What does class 5 mean
Tight fit
Whose mum is class 1 fit
Lewis’s mum cus she’s a loose fit
What class are aircraft screws normally in
Class 2
What is the maximum temperature low temperature locking nuts can withstand?
121 degrees
What is the crest on a screw
The prominent point of the thread
What is the temperature high temperature self locking nuts will act at?
121 degrees plus
What is the root of a screw
Bottom point of the thread groove
Where are slotted engine nuts used?
Engine only
What is a flank on a screw
The angle of the slope between the root and crest
What are anchor nuts used for?
Pannels regularly removed
Where are tinerman nuts used?
Any area which chance of magnetic interference
What is a stud (don’t say megs dad)
Shaft threaded on both ends
What is a thread angle
Angle between two crests
Describe a standard stud thread
Same throughout
Describe a waisted stud thread
Threaded each end, strength is retained, weight saved
What is the major diameter (screws) on a male and female
Crest to crest on male
Root to root female
Describe a stepped studs thread
Provide a stronger anchorage when used for softer material
Describe a shouldered stud thread
used when rigidity is required lateral stress
What are the 3 ways stud insertion are removed?
. Stud box
. Stud insertion tool
. Lock nuts
What is a heat coil insert and what does it do?
. Repairs stripped thread
. Must be 1/2 pitch below surface
What is a minor diameter (screws) on male and female
Root to root on male
Crest to crest on female
Name the 3 types of screw and describe them
. Machine screws - most common, structural parts, fairings
. Structural screws - same bolt strength, can be heat treated
. Self tapping screws - light weight material only, thin metal sheets
What is a pitch (screw)
The distance of one revolution
What are dowels?
Provide precision to alignment
What does BSW
British standard Whitworth
What does BSF stand for
British standard fine
What does BSP stand for
British standard pipe