Coaxiality is a positional tolerance. Form and position tolerances are a subarea of Geometric Product Specifications (GPS). They provide a way of using technical drawing entries to tolerate the geometric deviation of components. Coaxiality, or coaxiality, like other positional tolerances, limits the permissible deviations with respect to the position of two or more bodies relative to each other; more precisely, it limits the permissible deviations with respect to the congruence of rotational axes of three-dimensional elements. In this case, the axis of the toleranced surface must lie in a cylinder whose central axis is coaxial with the reference. Among other things, coaxiality is of particular importance for the production of technical drive shafts, because the diverse shapes of different shafts result in different force effects. Cams, journals, grooves and similar shaped elements have different effects when the shaft is in its operationally intended rotation. Thus, the greatest possible coaxiality must always be maintained for optimum stability and the longest possible service life. The two-dimensional counterpart of coaxiality is concentricity.