TM 55-2840-231-23
FRETTING - Wearing away of metal by rubbing against another metal (generally associated with press
fit or close fitting parts).
G
GAP - An opening or space; a break in continuity.
GLAZING - A hard, glossy surface.
GOUGE - A wide rough scratch or group of scratches, usually with one or more sharply impressed corners,
and frequently accompanied by deformation or removal of parent material.
GROOVE - A long narrow, continuous cavity or impression caused by pressure of a moving surface in
contact with the parent material.
I
INDICATIONS - Surface defect, not necessarily a crack.
INTERFERENCE - Anything that prevents a part, component, etc. from being assembled or disassembled.
L
LAPPING - Smoothing or polishing two surfaces, with or without abrasives, to a high degree of accuracy.
LEAK - The entering, escaping or by-passing (contrary to intention) of liquids or gases from their normal
passage or containment, usually caused by a hole or improper sealing. The act of leaking is called leakage
and the measurement of leakage is called leakage rate.
LOOSE - Abnormal movement of a part.
M
MATCHED - Fitted together or made suitable to be fitted together.
MATING SURFACES - Two surfaces that join or fit together.
N
NICK - A surface impression with sharp comers or bottom, usually caused by pressure or impact from a
sharp-edged foreign body. The parent material is displaced but usually none is separated.
NOISY - An abnormal sound condition of moving parts, usually an increase in volume or a change of pitch.
P
PEENING - Surface deformation.
PICKUP - Transfer of one material onto another.
PIT’TING - Very shallow depressions in a surface, usually caused by chemical reaction, (rusting chemical
corrosion).
Glossary-5
