The normal workshop accuracy (regarding geometrical deviations) depends on the accuracy of the (most inaccurate) machine tools, and on the accuracies of adjustment of the workpieces during re-chucking on the machine tool. The normal workshop accuracy can be assessed by the measurements of workpieces manufactured under normal workshop (production) conditions. The general geometrical tolerances should not be smaller than the normal workshop accuracy.

Because the general tolerances are so large that they are respected in any case, there is no disadvantage in applying them to features that would allow wider tolerances. ISO Tolerances for Holes(ISO 286-2)- 400mm to 3150 mm ISO Tolerances for Shafts(ISO 286-2)- 400mm to 3150 mm Remember - the information on this site is for general information purposes only and while we endeavour to keep the information up to date and correct, we make no representations or warranties of any kind, express or implied, about its. General tolerances for linear dimensions are given in tables 1. This concept, developed in the International Organization for Standardization (ISO) is illustrated in detail in this chapter. Tolerances for linear and angular dimensions. Before applying general tolerances, their concept must be agreed upon. Otherwise, the drawing would be embroidered with geometrical tolerance indications. As the principle of independency demands an indication for each requirement, it calls for the application of a standard on general geometrical tolerances (title block tolerances on geometry).