6.5 fasteners Flashcards
how do you measure screw thread pitch
screw thread pitch gauge
can a screw thread pitch gauge be used on internal and external threads
yes
what are the 5 classes of fit
loose
free
medium
close
tight
what class is aircraft screws manufactured with
class 2
for ease of assembly
what is female thread
internal thread
what is a taper thread
when it is formed on a conical part
when the thread is anticlockwise is it left or right
left
are most screws left or roght
right
where are multiple thread screws commonly found
industrial machines
valves
fire hydrants
aircraft landing gear
what is the lead
the amount of distance a nut travels in one revolution
in a double lead thread does it move 2x the amount as a single thread
yes
what is the length increments for aircraft bolt
1/8inches
what is diameter increments for aircraft bolt
1/16 inche
what is the size range for hex heads
AN3 - AN20
what is the bolt length
length from bottom of head to end of bolt
what is the grip length
length of unthreaded section
unless specified, what material is an aircraft bolt made of
cadmium plated nickel steel
what bolt size is forbidden by the faa
aluminium alloy bolts and alloy steel bolts
what letter identifies that a bolt has a hole drilled through it
A
what load is clevis bolt designed for
shear load
what load does eye bolts hold
tension
where are close tolerance bolts used
areas subject to pounding loads
what symbol identifies a close tolerance bolt
triangle
where can nylon self locking nuts not be used
in any location where temp could exceed 121c
what is a check nut
a seocnd nut which holds the primary nut in place
what are tinnerman nuts
cheap
stamped out of sheet metal
what are rivnuts used for
attach rubber de-icing boots
what is a stud
shaft threaded at both ends
what does heli coils do
protects against the wear from continual insertion and removal of bolts
what are the most commonly used threaded fastener
screw
whats the difference between bolt and screw
screw is mostly made from lower strength materials
the thread runs the full length of the screw but bolts usualy have an unthreadded section
what are machine screws used for
attaching fairings
inspoection plates
fluid line clamps
light str4uctural parts
what class fit does screws usualy have
class 2
what are structural screws made of
alloy steel
where are self tapping screws used
to hold thin sheets of metal
plastic
plywood
what is a gimlet point on a screw
a sharp point
what is a type A screw
has a gimlet point (sharp)
what is a dowel
solid cylindrical rod
used where precision alignment is used
what is a pip pin
non threaded fastener for quick removal of parts without tools
works by pressing in a button to remove a ball which locks the pin in place
when are lock washers used
when the joint is not structurally criticalw
what are lock washers made of
steel
how does spring washer work
coil is compressed, creates friction, prevents nut from vibrating loose
how does tab washer work
one tab is bent across the flat of the nut
cant be used again
can you reuse tab washers
no
what is a shakeproof washer
steel washer with serrations
the serrations prevent the nut from undoing
what is the minimum amount of twists per inch for locking wire
6-8 twists per inch
where are pal nuts ideal for
ideal for applications where frequent load changes tend to loosen conventional nuts
what are the 3 common types of quick release fassteners
dzus
airloc
camloc
whats camloc also referrd as
quarter turn
what loads do taper pin withstand
shear loads
what is the most common used rivet
solid shank
before being driven, how much should the rivet extend the base material by?
1.5x the diameter
how to identify if a bolt has a hole drilled through it
A is used in the part code
aluminium of 1100 is used for what applications
low strength
