This standard specifies the basic terms and definitions of threads. This standard applies to symmetrical and asymmetrical threads, or cylindrical and tapered threads. When more than one term corresponds to a definition, the bolded term should be preferred. Appendix A lists some terms that are not defined in the main body of the standard. See Appendix B for French, German, Japanese and Swedish equivalents of Chinese and English thread terms.
GB/T 14791-2013 Referenced Document
GB/T 1800.1-2009 Gemetrical Product Specifications(GPS).Limits and fits.Part 1:Bases of tolerances,deviations and fits