TM 1-2840-252-23-3
GLOSSARY (Continued)
Definition
C (Continued)
Corrosion Pitting................................ ........ Irregular surface depressions having ragged edges due to
metal removed caused by corrosive substance adhering to
exposed surfaces.
Corrugated ................................ ................ The forming and shaping of sheet metal into wrinkles or
folds or into alternating ridges and grooves.
Crack................................ ......................... Parting of parent metal.
D
Dent ................................ .......................... A completely smooth surface depression caused bypres-
sure or impact from a smooth ball-like foreign object. The
parent material is displaced, but usually none is separated.
Desiccant................................ ................... A drying agent; usually placed in containe s along with
r
parts being stored, to absorb moisture and preventcorro-
sion.
Diagnostic Equipment................................ Test equipment used to determine what the defective part
is.
Distortion ................................ ................... Twisting or bending out of a normal, natural or original
shape, usually caused from being exposed to excessive
pressure or temperature either when restrained orunre-
strained.
F
Fatigue ................................ ...................... The progressive weakening of a material under repeated
cycles of stress.
Foreign Material ................................ ........ See Contamination.
Foreign Object................................ ........... Any object such as a tool, piece of equipment, engine part
(nut, bolt,.lockwire) that could in any way damage the en-
gine.
Fraying ................................ ..................... Wearing or rubbing of areas, generally used in reference to
damage on wire-braid covering (of Teflon hose) or on ther-
mocouple harness.
Fretting ................................ ...................... Discoloration or damage caused by rubbing, chafing, or
wearing away of original surface material resulting from
movement of contacting surfaces. Can cause grooving in
severe cases.
G
Gouge ................................ ....................... A wide rough scratch or group of scratches,usually, with
one or more sharply impressed corners, and frequently ac-
companied by deformation or removal of parent metal.
Glossary-2
