1. the material can be 20CrMnTi, 16MnCr5, 40#,45#, 40Cr, 42CrMo ... treatment can be case hardening, nitrogen, quench We can supply:1. gear modul 0-6;2. the gear quality can be ... 5,6,7,8 grade;3. the material can be carbon steel, nylon, plastic;4. the heat treatment can be case hardening ...