hardware quiz

Condition prohibiting the use of a self-locking nut

When the bolt or nut is subject to rotation.

Operating condition assumed by standard bolt torque values

Clean, dry threads.

Head marking used to identify an NAS close-tolerance bolt

Triangle marking on the bolt head.

Standard installation orientation for aircraft bolts

Head positioned facing upward or forward.

Safetying device required for securing a castle nut

Cotter pin.

Type of load an AN Clevis bolt is designed to carry

Shear loads only.

Method used to properly secure a Clevis bolt and fork-end connection

Snug shear nut secured with a cotter pin, ensuring no strain is placed on the fork.

Standard thread fit class specified for aircraft bolts

Class 3 fit.

Standard reference publication used when specific bolt torque values are omitted

AC 43.13-1B or standard torque tables.

Correct procedure when a castle nut fails to align with the cotter-pin hole within torque limits

Change the washer or nut and try again; never over-torque to force alignment.

Mechanism providing the locking action in a fiber-type self-locking nut

Unthreaded fiber insert.

Required action if a fiber or nylon self-locking nut can be turned through its insert by hand

Reject and replace the nut.

Required relationship between bolt grip length and material thickness

Grip length should equal the total thickness of the material being fastened.

Definition of bolt grip length

The unthreaded portion of the bolt shank.

Bolt head marking indicating a standard steel bolt

Cross or asterisk.

Bolt head marking indicating an AN corrosion-resistant steel bolt

Single raised dash.

Measurement unit for rivet diameter in standard rivet part numbers

Thirty-secondths of an inch ($\frac{1}{32}\,\text{in}$).

Measurement unit for rivet length in standard rivet part numbers

Sixteenths of an inch ($\frac{1}{16}\,\text{in}$).

Dimensions indicated by rivet part number MS20430AD-4-8

$\frac{1}{8}\,\text{in}$ diameter by $\frac{1}{2}\,\text{in}$ length.

Primary structural distinction between tension and shear Lockbolt fasteners

The number of locking-collar grooves.

Key structural and installation advantages of HI-LOK fasteners

Lightweight, high strength, high fatigue resistance, impossible to over-torque, and installable using ordinary hand tools.

Material requirement for cotter pins installed near magnetic compasses

Corrosion-resistant steel.