Imperfection

1) When referring to the physical condition of a part of metal product, and departure of a part of metal product, any departure of a quality characteristic from its intended level or state. The existence of an imperfection does not imply nonconformance, nor does it have any implication as the usability of a product or service. An imperfection must be rated on a scale of severity, in accordance with applicable specifications, to establish whether or not the part or metal product is of acceptable quality. 2) In crystallography, any deviation from an ideal space lattice.