ASME Y14.7.1-1971

â??This standard is no longer an American National Standard or an ASME-approved standard. It is available for historical reference only.â?� This Standard sets forth methods to be followed for specifying drawing data for gears operating on axes which are parallel. It is the purpose of this Standard to provide formats, nomenclature, and definitions for the following types of gears: Spur, Helical, Double-Helical, and Spur and Helical Racks. The minimum data for the various gear types are defined. Where additional data are required, methods for specifying these data are shown. Slight deviations for critical applications are recognized, provided general formats are maintained.