Tolerance - Limitation, usually quantitative, determining the allowable range of accuracy   for (1) a quantity property (dimensional, locational, material makeup, etc.) of a manufactured part or (2) any manufacturing process or capabilities of a machine tool.

Tolerances are qualitatively described by the terms loose and tight. A tighter tolerance indicates that the value is smaller, a looser tolerance means that the tolerance is larger.

Precision manufacturing requires tight tolerance manufacturing processes.