Gloosary Of Terms

Glossary Of Terms
An advisory circular in book form,
issued by the Federal Aviation Administration,
which covers acceptable methods, techniques,
and practices for aircraft inspection and repair.

AC 43.13-lA

Airloc A fastener used to lock engine cowling or

Bearing load The load applied by one item placed

on, or clamped between, another item; e.g. t he
load applied to the structureunder a rivet head
or bolt head.
Beef-up To strengthen an area which is showing

signs of fatigue failure.
Beehive spring The coiled set retainer spring of a

pneumatic rivet gun.
Bend allowance The amount of material actually

used in a bend of sheet metal.
Alodining A treatment applied to the s urhce of

aluminum alloy to prevent corrosion and provide a n excellent paint base.
Achemical surface treatment to prepare aluminum for finish painting.

Alodizing

Bending The stresses in an object caused by a load

being applied to the one end while the other is
restrained. This results in a tensile load on one
side and a compressive load on the other.
Bend radius The radius of the inside of a bending

Aluminum alloy A physical mixture of metals in

which aluminum isthe base and other metals
are added for specific characteristics.

sheet metal.
Bend tangent A line made on sheet metal layout

to indicate the beginning of a bend.
Heating of an alloy to a temperature
called solid solution temperature, allowing it to
cool slowly at a controlled rate through its critical range for the purpose of inducing softness.
Results in removal of formerheat-treatment
strain hardening and internal stress.

Annealing

The positive pole of an electrical device. In
the anodizing process, the aluminum part is the

Anode

A n electrochemical action which causes
aluminum oxides to solidify on the surfaces of alu-

Bi-metallic The fusion of two different metals on

t he same primary member; e.g. a Cherrybuck
rivet.
Boeing rivet

A modifiedAN470 rivet.

Brazier head rivet An aircraft rivet with a large,

thin head, specification AN455. This rivet has
been superseded by the AN470 universal head
rivet.

Anodizing

A hard, steel bar having a polished face, used to form the upset head of
an aircraft.

Bucking bar

Anti-drag wire A wire brace acting in a diagonal

direction that opposes a drag wire.
Ballizing The forcing ofa ball into an undersize

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hole, causing deformation and plastic recovery
to occur. The result is a hardened cylindrical
wall that has high resistance to bearing and
shearing failure. The area around the hole becomes preloaded.

Bucktail The driven end of a solid-shank rivet.

Also called shop head, upset head, driven head,
or bucked head.
Bulbed Cherrylock rivet' A special blindrivet man-

ufkctured by Cherry, in which the stem is locked
into the hollow shank by a locking collar which
swages into a groove in the stem.

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Bulbed end A formed end on a blind rivet which is

Clamp-up The drawing together of two or more

sheets of aluminum skin and parts.

inaccessible during installation.
caliper, inside A measuring instrument with twoadjustable legs, used to determine an inside measurement. Once the distance has been established, t he actual measurement is made with a
steel scale or a micrometer or vernier caliper.
Caliper,micrometer A precision measuring device
having a single movable jaw, advanced by a

Cleco A sheet metal clamp used to hold parts in

place prior to driving the rivets.

Coldworking Any mechanical processwhich in-

creases metal hardness. May be accomplished
by hammering, rolling material through rollers, or pulling through dies.

screw. One revolution of the screw advances the
jaw 0.025 inch.

Compound curve Curvature of a metal surface i n

caliper, utside A measuring device having two
o
movable legs, used to determine the distance
across an object. Once the distance has been...