General Tolerances Spec Table
General tolerances apply to dimensions on drawings where no individual tolerance is specified. Per KS B ISO 2768-1, four grades are defined: fine (f), medium (m), coarse (c), and very coarse (v), designated in the drawing title block. Individual tolerances must be specified for functionally critical dimensions; general tolerances should only be applied to non-functional dimensions.
Frequently Asked Questions
What is a general tolerance (ordinary tolerance)?
Tolerances automatically applied to dimensions without individual annotations. Per KS B ISO 2768-1 (ISO 2768), there are four grades: f (fine), m (medium), c (coarse), and v (very coarse).
How do I select a general tolerance grade?
Use f (fine) for precision machinery and optics, m (medium) for general machining, and c (coarse) for sheet metal and welded structures. State in the title block, e.g., "General Tolerance KS B ISO 2768-1 – m".