The helical internal ring gear was produced by power skiving craft ,For small module internal ring gear we often suggest to do power skiving instead of broaching plus grinding ,since power skiving is more stable and also has high Efficiency ,it takes 2-3 minutes for one gear ,accuracy could be ISO5-6 before heat treat and ISO6 after heat treatment .
Module is 0.8 ,teeth :108
Material :42CrMo plus QT ,
Heat Treatment :Nitriding
Accuracy: DIN6