When is a part considered a reject?

A part is considered a reject when its dimensions are out of tolerance because adhering to specified tolerances is critical in precision machining. Tolerances define the allowable variations in dimensions, ensuring that parts fit properly and function as intended in an assembly. If a part does not meet the established tolerances, it cannot fulfill its purpose, leading to potential failures or malfunctions in the final product. Thus, being out of tolerance directly affects the integrity and performance of the component, warranting its classification as a reject.

While producing a part incorrectly may also render it unusable, it may not specifically pertain to the dimensional accuracy that defines a reject situation. Additionally, issues like improper painting or the need for rework, while possibly indicating quality concerns, do not necessarily classify a part as a reject in terms of its dimensional requirements. The critical focus on tolerances as standards of acceptability is what makes the option about being out of tolerance the right choice for defining a reject.