This Standard provides definitions of terms, tables of preferred basic sizes and standard tolerances, a series of standard fits to cover most engineering requirements, and information for the design of special fits for use where standard fits are unsuitable.
It is not the intention of this Standard to specify fits and tolerances for specific applications, but to afford a range from which the designer can choose the most suitable for his or her particular application.
The names and descriptions of fits in Clause 4 are intended as general descriptions to assist the designer in making his or her selection.
This Standard applies particularly to fits between non-threaded cylindrical parts, commonly referred to as holes and shafts, in which case the term size refers to the diameter of the mating parts. The data may be applied also to fits between mating parts other than cylindrical, in which case the size refers to a length, width, or other dimension, instead of a diameter.
Allowances and tolerances agree with ISO recommendations and the original ABC agreements as indicated in the Preface.