This part of GB/T 21466 specifies the empirical allowable values of h, T and P. Note: For certain applications, for example when taking into account information provided by the manufacturer, the above empirical values may be modified. Calculation examples and symbol definitions are given in GB/T 21466.1-2008.
ISO 7902-3:1998 Referenced Document
GB/T 1800.4-1999 Limits and fits Tables of standard tolerance grades and limit deviations for holes and shafts*, 1999-09-03 Update