Table 2-2. Propeller Defects
A damaged or worn area caused by hard usage or heavy blows.
An area of damage caused by parts sticking together.
Raised areas of plate indicative of a lack of bond between plating and base
metal or overheating above the melting temperature of the plating material.
A bent blade usually caused by foreign objects.
Having one or more indentations on bearing races, usually caused by high static
loads or application of force during installation or removal. Indentations are
rounded or spherical due to the impression left by the contacting balls or rollers
of the bearing.
A ragged or turned out edge usually resulting from machine processing.
A condition caused by a rubbing action between two parts under light pressure
which results in wear.
A condition in which there are numerous small cracks in the metal, usually
caused by machine processing.
The breaking away of pieces of material which is usually caused by excessive
stress concentration or careless handling.
Damage from scratching on the external boundary or surface of an object.
Loss of metal by a chemical or electrochemical action. The corrosion products
generally are easily removed by mechanical means. Iron rust is an example of
A partial separation of material usually caused by vibration, over-loading,
internal stresses, defective assembly, or fatigue. Depth may be a few
thousandths to the full thickness of the piece.
A small, rounded depression in a surface usually caused by the part being struck
with a rounded object.
Material that has accumulated in recessed areas.
Discoloration is due to the effects of heat in the presence of oxygen. Surface
colors may range from light straw to gray depending on the environment
temperature and the thickness of the oxide film that is formed on the surface.