This standard specifies the normal modulus of spur and helical involute spur gears for general machinery and heavy machinery. This standard does not apply to automotive gears.
GB/T 1357-2008 history
2008GB/T 1357-2008 Cylindrical gears for general engineering and for heavy engineering.Modules
1987GB/T 1357-1987 Modules of involute cylindrical gears