AMT Hardware Flashcards
AN804
Bulkhead Tee,
Bulkhead on run
AN806
Pressure Plug
AN814
Bleeder Plug
AN815
Union
AN816
Pipe to 37⁰ Flare,
Straight
AN818
Tube Nut
AN821
90⁰ Elbow
AN standard steel bolt
AN standard steel bolt
AN standard steel bolt
AN standard steel bolt (corrosion resistant)
AN standard steel bolt
AN standard steel bolt
AN standard steel bolt
AN standard steel bolt
Special bolt
Special bolt
Drilled head bolt
Special bolt
NSA Close tolerance bolt
Aluminum alloy (2024) bolt
Magnetically Inspected
Orange-dyed magnetically inspected
Clevis bolt
Reworked bolt
Low strength material bolt
What is the purpose of standards?
- Hardware meets or exceeds specs
- Stays consistent to same reference point
- Creates trust, integrity on regulated products
AN
Airforce Navy
MS
Military Standard
NAS
National Aerospace Standards
SAE
Society of Automotive Engineers
AMS
Aeronautical Material Specification
MIL
Military Specification
AN bolt length sized in ____increments
1/8”
AN bolt diameter sized in ____ increments
1/16”
Combined washer height/thickness can be no more than ____
1/8”
IPC
Illustrated Parts Manual
-Lists the specific part numbers of hardware required for relevant installation
STC
Supplemental Type Certificate
-A civil aviation authority-approved major modification or repair to an existing type certified aircraft, engine or propeller.
What two standards combined to make AN standards?
AS-American standard
UN-Unified National
Sharp V
Whitworth
-55⁰ angle
Buttress
Square
ACME
Worm
The body drill size is equivalent to ____ of a thread
Major diamater
The inside diameter of nut is equivalent to the ____of a thread
Minor diameter
Class 1 is a _____thread fit
Loose
Class 2 is a ____ thread fit
Free
Class 3 is a ___thread fit
Medium
Class 4 is a ___thread fit
Close
Class 5 is a ___thread fit
Tight
Major diameter
Pitch diameter
Minor diameter
Angle
Root
Crest
Pitch
If the PN is M10 for a metric thread that means:
The major diameter is 10 mm (milimeters)
Metric threads have a _____angle
60⁰
The pitch of a P/N M10x1.0 is
1.0 mm
AN bolt are what thread standard?
National Fine
National Fine thread standards are typically for ____requirements
High torque
National Coarse threads are typically used for _____ requirements and lower cycling loads.
Lower torque
AC strength can reach _______as compared to hardware at only 55,000 psi
125,000psi
A/C hardware is _____plated as compared to regular hardware which is not plated
Cadmium
A/C hardware is _____ whereas hardware is not.
Certified/approved
True or false, AC hardware cannot be traced
False. By having special standards and regulations, aircraft hardware is traceable and therefore holds its integrity as a reliable product.
Bolt diameter at 1/16” increments is slightly ____ than nominal
Less
Bolt length at 1/8” increments is slightly ____ than nominal
More
In bolt AN4-4A, A stands for what?
A is absent hole from shank of bolt.
In AN4H-4A, H stands for what
H is hole in head of bolt, A is absent hole from shank
What does DD indicate in bolt naming?
Aluminum
In AN17, what does 17 mean?
Close tolerance bolt
AN73-4, 7 indicates what
Engine bolt
AN24, 2 indicates
Clevis bolt
P/N MS-20004 to MS-20024 is what
Internal Wrenching bolt
What special requirement for an internal wrenching bolt?
A special countersunk washer is required (MS20002C)
What is unique about an internal wrenching bolt? (MS20002)
It has a radius between shank and head to prevent stress risers from a sharp edge. A corresponding washer to that radius is required as well.
Also has 160,000 psi tensile strength, used for high load areas such as wing attachments.
Internal wrenching bolt
-Look for radius at head
Identify
AN Aircraft Navy
- 17 = close tolerance
- 3 = diameter in 1/16”
- 10 = length in 1/8 (1”)
Identify
AN Aircrat Navy
- 7 is engine bolt
- 3 is diameter in 1/16
- 4 is length in 1/8
- fine thread
- If an A after,(AN73A-4) = COARSE
12 point washer head bolt
Flush head bolt
What is the torque measurement for metric bolts
Meters or deca-newtons
Wrench size for AN5 bolt diameter
1/2
5/16 add 3/16 = 8/16 to 1/2
Wrench size for 3/8 AN6
9/16
6/16 add 3/16 = 9/16
With bolt installation:
- Washer like surface material
- Grip length same as joined material thickness
- Install as per MM, SID, STC, AD
If grip length is too long for materials joining you should
Use washer or smaller bolt.
All bolt heads and LH threads installed:
Up, forward and outboard
Drill hole for bolts, loose fit is
Larger than bolt shank by .002 to .005
Drill goles for bolts, push fit is
Reamed to fit, allows bolt to be installed with steady hand pressure
Drill holes for bolts, tight drive fit is
Installed with a few blows of a hammer
Drill holes for bolts, interference fit is
Bolt diameter is larger than hole, hole is heated, bolt is chilled prior to installation.
Clevis bolt
Eye bolt
Jo bolt
Lockbolts
Hi lok
What class fit is a nut
Class 3
What two types of nuts are there?
Self locking and non self locking
Non self locking nuts
True or false, self locking nuts must be used on parts subject to rotation
False. They must NOT.
Can you install a self locking nut above a turbine engine inlet?
No, it could fall off into the turbine engine inlet and become a big problem.
True or false. Self-locking nuts should be installed on components that are routinely disassembled.
False.
Nylon locking nuts must not be used
In engine compartments or electrical terminals, they will melt from high heat.
Each removable fastener must incorporate two retaining devices IF the loss of such fastener would preclude what?
Continued safe flight and landing
Fasteners and locking devices must not be adversely effected by what?
Environmental conditions associated with particular installation
No ______ nut may he used on any bolt subject ti rotation in operation unless non-friction locking device is used in addition to the _____device
Self-locking
If the inside diameter of a nut is .216, according to the table, it is a what?
A 1/4” -28 nut
AN310 CASTLE NUT
AN320 SHEAR CASTLE NUT
AN315 PLAIN NUT
AN316 CHECK NUT
AN340 MACHINE SCREW NUTS
AN345 MACHINE SCREW NUT
FINE
AN355 SLOTTED ENGINE NUT
AN360 PLAIN ENGINE NUT
Palnut
In safety of nylon self locking nuts, how many threads must show
1 to 3
What temperature do nylon self locking nuts work below
250⁰F
Do not use a nylon self locking nut if
It has no drag
If more then 3 threads showing, there is danger of nut thread ____
Bottoming out on bolt shank
AN365 NYLON LOCK NUT
AN365-428A, A means
Non-metallic insert
AN465-428C, C means
All-metal locknut
AN364 LOW PROFILE NYLON LOCK NUT
A self locking castle nut with nylon insert provides additional or double what
Safety
AN363 AND MS21042 HIGH TEMP LOCK NUT
What is swaged?
To reduce or taper by forging or squeezing.
Plain washer
Large area washer
Split lock washer
Shake proof lock washer
High strength washer
High strength countersunk washer
Washer AN960
Cadmium plated steel washer
Washer AN960C
C means corrosion resistant steel
Washer AN960B
B is brass
Washer AN960D
D is aluminum alloy
Washer AN960PD
PD anodized aluminum alloy
Washer AN960-416L
L=Light 1/2 thickness
-used for lining up cotterpin hole to castellated nut
Two types of machine screws
Structural and non structural
Pan head
100⁰ countersink
Washer head
Filister head
Two types of screw points
Sharp points (gimlet) and blunt points (various)
Two-lug anchor nut
One lug anchor nut
Corner anchor nut
Right angle anchor nut
High temperature two-lug anchor nut
Two lug floating anchor nut
Instrument nut
Anchor type tinnerman nut
U type tinnerman
Cotterpins are measured in length how?
By the shortest leg
Tapered pins are used in shear loaded joints where absence of ____is essential
Play/movement
When choosing a bolt:
Grip length = joined material thickness
Washer under nut
Safety, 1 to 3 threads showing after engagement
Choose proper hardware
.250 hole
Total material thickness is 1.315”
Use general purpose AN bolt
Use castellated nut, washer and cotterpin
AN4-16 bolt AN960-416 washer AN310-4 nut AN380-2-2 cotterpin MS24665-132 Cotterpin
Choose proper hardware
.375 hole
Total material thickness is 2.500”
Use regular AN bolt
Use nylon lockout, with plain washer
AN6-31A Bolt
AN960-616 washer
AN365-624A Nut
Fittings
Uses familiar UNF thread, non-tapered thresd design, seals angled mating surfaces
Tube thread
Fittings
Uses NPT thread, tapered thread design, seals on tapered threads
Pipe thread
Fittings
37⁰ chamfer, coarse thread, blue or black in color. Accepted in aviation maintenance.
AN Fittings
30⁰, gray or yellow in colour, finer thread, not accepted
AC Air Corp
These fittings go through structure and bulkheads, boss o-rings installed into castings
Bulkhead tube fittings
When installing o rings, what indicates a proper fit
O ring is pinched into fitting to prevent leaks, fitting is chamfered so o ring is not cut
Tubing is sized by _____ diameter
Outside
Flexible hose is sized by
Inside diameter
Low pressure tubing
Medium pressure tubing
High pressure tubing
What type of aluminum is used in an A-type aircraft rivet
1100
What mark is on the head of an A-type rivet
No mark, plain
What type of aluminum alloy is used in am AD type rivet
2117-T
What mark is on the head of an AD type rivet
Recessed dot
Why are A type rivets not approved for structural use?
Too soft, only used for non structural softer materials
What are the two alloys for ice box rivets
2017-T and 2024-T
Why are ice box rivets to be kept in sub-freezing temperatures after being heat treated
They age harden at room temperature in minutes
What type of aluminum alloy is in B rivet
5056-T
What are B rivets used for
Rivet magnesium alloy structures, corrosion resistant traits
What type of metal is an F type rivet
Corrosion resistant steel
What are F type rivets used for
Riveting corrosion resistant steel firewalls
What is an M type rivet made of
Monel
What are thebtwo most common rivets
Common solid shank and blind rivets
AN for round head rivet
AN430
AN number for flat head rivet
AN441
AN number for universal head
AN470
MS number for universal head rivet
MS20470
AN number for 100 degree countersunk rivet
AN426
MS number for 100 degree countersunk rivet
MS20426
True or false
Pull type lockbolts are equal strength to AN bolts and are difficult to install. They are also lighter
False, they are easy and quick to install.
Where can you find the correct hardware part numbers to assemble on certified aircraft?
The Maintenance Manual (MM) and Illustrated Parts Catalog (IPC)
What is the most common head marking on am AN standard bolt?
A raised dash or asterisk
What class fit are AN bolts and Nuys manufactured with?
Class 3, medium fit
Aircraft nuts can be divided into 2 types, what are they?
Self-locking and non-self-locking
Where should self-locking nuts NOT be used?
- Parts subject to rotation
- Where they can fall into an engine inlet
- On access panels routinely disassembled
What type of bolt installation for a castle nut?
With a drilled shank bolt in a shear load only
Hardware required for a .250 diameter hole joining two pieces of aluminum 1.315”. What is the bolt, castellated nut, washer and cotterpin?
AN4-16 bolt
AN960-416 washer
AN310-4 nut
AN380-2-2 cotterpin
