Abrasion, Arc Burn, Back to back imperfection, Bend, Blending, Blistering

Tabel 2.1 a

DEFFECT	DESCRIPTION
Abrasion	A roughened area. Varying edges of abrasion can be describe as light or heavy, depending upon extent of reconditioning required to restore surface. Usual cause is resent of fine unwanted material between moving surfaces
Arc burn	Evidenced by a small circular or semi-circular heat affected area on the surface of a part that may contain shallow pitting, remold, or crack. Blades with arc burn are not acceptable for further service.
Back to back imperfection	Imperfections on the opposite faces of a specific wall (or weld) which normally are opposite each other. This condition is considered evidence of a single through-wall imperfection.
Bend	General distortion in stucture as distinguished for alocal damage in comformation. Usual causes are uneven aplication of heat, excessive heat or pressure, or forces defined under stresses
Blending	An operation which removes an irregularity from a surface and results in a shallow, smooth depression.
Blistering	Raised areas that indicate separation of surface from base. Usually found on plated or painted surfaces. Associated with flaking or peeling. Usual cause is imperfect bond with base, usually aggravated by presence of moisture, gas, heat, or pressure