M6.5pt2 Fasteners Flashcards
What does a spring washer do?
Creates spring compression and a friction lock, cannot be reused
What does a tab washer do?
Has to be bent over the bolt, cannot reuse
What is a shake-proof washer?
Sharp edges of a washer dig into material of bolt, can only be reused if the springiness is retained
What is a lock wire and what does it do?
Single twists and double twists, can only lock a maximum of 3 bolts together, use of different thickness wire to lock in bolts
What are the 2 lock wiring methods?
. By hand
. Wire locking pliers (twisters)
What is a locking plate?
. Plate goes over a nut to prevent it loosening
. Reusable
What is a pal nut?
Spring lock action nut
How’s spring washers work
A small spring is inserted and causes it to friction lock preventing it to become undone
How is 1100 aluminium alloy identified
Plan head
the letter A
Low strength rivet, very soft
What is a quick release faster?
. Fast unlocking
. Vibration resistant
How do tab washers secure a nut
It’s put in between nut and surface and then the tabs are folded up
Which one of the washers are reusable
Shake proof
What’s locking wire made from
Stainless steel and copper
How is 2117 aluminium alloy identified
A dimple on the head
the letter AD
Medium strength rivet, most used
No heat treatment required (already done)
What’s the most common quick release fasteners
Dzus
What are the two types of Dzus and what’s the difference
Light and heavy ( heavy requires a grommet)
How is 5056 aluminium alloy identified
A cross
the letter B
5% magnesium, Al alloy
Prevent dissimilar metal corrosion
Rivet onto magnesium only
What is a taper pin?
. Any joint with shear load
Where would taper pins be used
In a place where a shear loading is applied
What is a split pin?
. Cadmium plated carbon or cress
What is the most common key?
Woedruff key
What are the 2 rivet codes and what do they mean?
426 - countersunk head
470 - universal head
In a rivet code what does the number before and after the dash mean?
Diameter 1/32 - Length 1/16
What’s the most common key
Woodruff key
What type of metal would have to be dimpled instead of countersunk?
Thin metal sheets
What type of nuts are split pins used with
Castlated nuts
What is a 426 rivet
A countersunk rivet
What’s a 470 rivet
Universal head
How is 2017 aluminium alloy identified
A raised dot
the letter D
Require heat treatment
Freezer delays age hardening
‘Ice box rivets’
How is 2024 aluminium alloy identified
Two dashes
the letters DD
Requires heat treatment
Ice box rivets
what do the numbers represent in rivet codes
The 3 digit code- is the head style (470 or 426)
The second to last one is the diameter of the rivet (measure in 1/32)
The last one is the length of the rivet (measure in 1/16)
what do the numbers represent in rivet codes
The 3 digit code- is the head style (470 or 426)
The second to last one is the diameter of the rivet (measure in 1/32)
The last one is the length of the rivet (measure in 1/16)
How is 7050 aluminium alloy identified
A raised circle
the letter E
Harder than 2024
Requires heat treatment
Which type of rivet is most common universal or countersunk
Universal
How is CRES aluminium alloy identified
no markings
the letter F
Used in firewalls and exhaust
Why are counter rivets more commonly used on aircraft surface instead of universal
Because they’re more aerodynamic
How is Monel aluminium alloy identified
2 : on head
the letter M
Instead of CRES rivets
How are 1100 rivet aluminium alloys identified
By letter A
Have no marking
What is difference between a special rivet to a standard rivet
Special rivets, you only have access to one end of the rivet.
More expensive
How are 2117 identified
With letters AD
And a dimple in head of rivet
How are 5056 rivets identified
With the letter B
And with a cross on the head of the rivet
What are the 4 mechanical lock rivets
Huck lock
Cherry lock
Olympic lock
Cherry max
How are 2017 rivets identified
Identified with the letter D
How a dot on the top
How are 2024 aluminium rivets identified
With a DD
Has a double dash on rivet head
What lock rivet replaces solid shank rivets
Huck lok
How are CRES rivets identified
With the letter f
What does a cherry lock ensure
The lock rinks endure stem is locked into place
Needs a specific tool
What’s the economic advantage of cherry max rivets over cherry lock rivets
Cherry max only requires one size puller for installation of all sizes
What’s the difference between a cherry lock and cherry max
Cherry max, any tool can be used for installation
What is a disadvantage of Olympic lok
Needs specific installation tool
What’s the difference between Hi lok and hi lite fasteners
Hi lite it’s lighter than hi lok
What type of fastener is the strongest
Taper lok
How can you identify different lock bolts
Colour coded
What tools do you use for Hi loks
Allen key or hex drive
Which is the strongest special fastener
Taper lok
Also radial compression over shank that evens out stress
How would you remove special fasteners
Turning with wrench and pair of vice grips
Or
Mallet to tap out remaining faster
Or
Chisel to split collar
Why is hite lite better than hi lok
15% lighter
What is the angle for AN fitting
37%
What is the angle for AC fittings
35%
What colours would define an AC fitting
Yellow and grey is also shorter than AN
What colours define AN fittings
Blue and black
Longer than AC
What are the two types of flareless fittings
MS
Harrison
What principle do MS and Harrison fittings follow
Ball bush principle
What is the main advatanage of Harrison
Vibration resistant
Simple tooling
How would you identify if a flareless fitting is made out of aluminium alloy
the letter D
How would you identify if a flareless fitting is made out of cadmium plated steel
Non just plain
How would you identify if a flareless fitting is made out of CRES
the letter S
What is a swaged fitting used for
Repairing sleeve
What are the advantages of swaged fittings
Quick
In situational
What do flexible fluid lines do
Connect stationary to dynamic
What does the inner layer of a flexible fluid line have to be
Chemically compatible (Teflon)
Compatible with nearly all fluid
What are lay lines
Twist indicators
(1/16)
Prevent hose twisting
What are the pressures for flexible fluid lines
Low - 600psi
Medium - up to 3000psi
High - above 3000psi
What are the disadvantages of swaged end fittings
Cannot be removed or reused
What are blanking caps used for
Covers end of fitting to prevent fod or cross contamination when changing
When are quick disconnect couplings used
One hand operation to connect and disconnect without need for further equipment, very quick and easy
What is a swivel fitting
Reduce length of hose between connections
Eliminate the need for bent tubing
