This standard specifies the error definition, code, accuracy grade, tooth blank requirements, inspection and tolerance, backlash and drawing marking of involute cylindrical gears and their gear pairs. This standard applies to involute cylindrical gears and their gear pairs, for parallel shaft transmission. Its normal modulus is greater than or equal to 1 mm; the basic tooth profile is in accordance with GB 1356. When the gear specification exceeds the range listed in this standard (the normal module is greater than 40 mm, the diameter of the index circle is greater than 4000 mm, the effective tooth width is greater than 630 mm), it can be specified in Appendix A (supplementary).
