SDTP 215 Hardware Exam (AXT)

What loads or load may a clevis pin be used for?

Shear Loads only

List the 3 hardware standard commonly used in aviation?

Airforce-AN,

Military- MS

Nationalaeropace standard NAS

Type of load that a bolt is under a 2 moving plate in opposite direction that is trying to split the bolt in half.

Shear

Defintion of an “R” in a AN525-832R8

Requires a Philip head screwdriver

Definition of a “A” in a bolts part number?

Undrilled shank

What is the type of loads can a normal AN bolt be used?

Shear & tension

Is taper pins able to be used for both shear & tension load?

NO, only shear loads

Temperature for a AN 365 self locking nut should not be exceeded at?

250 F

What is a grip length of a bolt?

Length of unthreaded portion of the bolt

If a bolt has an triangle with an X inside it, marked on top of the head what does this indicate?

NAS close tolerance

Define which class of thread that fits aircraft bolts manufactured to?

Class 3 fit

What nut would you use for an AN4-6 bolt

AN310-4

If no specific instruction on how a bolt be installed, bolt head should be installed in what direction?

Upward or forward direction

Which class of thread fit requires wrench to be used to install start to finish?

Class 4

How is length of a bolt measured and what increments are used for?

Measured from below the “head to the end of the threaded portion”. 1/8 inch increments

What increments used to measure the bolts diameter ?

Measured 1/16 inch increments

How should we secure a nut that is prone to rotate?

Cotter pin

Which screw can be used in a lieu of structural bolts?

Structural Screws

What does clevis bolt & clevis pin look like, describe it

What is a Class 3?

Medium fit

Specific manufactured to aircraft bolt (AN)

What is a class 4?

Close fit, propeller & engine mounts

wrench/socket to be used to install start to finish

What is class 1 fit?

Loose fir

sheetmetal screws

What is a class 5 fit?

Tight fit

requires force to install

wing/stabilizer attachment bolt

What does this hardware code mean AN6CH-8A

AN= standard Air Force- Navy

6= Diameter 1/16

C= Type of material C- corrosion resistant

H=drilled head (no letter not drilled, meant for lock wire)

6= length in 1/8

A= Hole in bolt thread (No letter no hole, meant for cotter pin)

What are Anchor nuts?

They are used to rivet to structure blind holes.

What are taper pins?

Shear only

Tapered bolts which has threaded shank or a cotter pin hole at the end

Why is it critical ensure the correct grip length to install a bolt?

• Grip length too long → add plain washers

• Ensure 1–3 threads protrude past the torqued nut

• Grip length too short → unacceptable

• No threads allowed inside the structure

• No unthreaded shank exposed after torquing

What is the main function of plain washer when steel bolt is an aluminum structure?

So that metal corrosion goes to the washer & not aircraft structure.

Aircraft screws come in three main types what are they?

Machine screws (AN515)
Structural screws (AN525)

Self taping sheet metal screws

Aircraft screws have AN code to indicate

Screw style
Application used for

thread pitch

Diameter

R indicate to use Philip screwdriver

Aircraft nuts come in two main types

Non- self locking - Any application prone to rotation

Self locking - Low temp