... treatment: annealing, normalizing, carbonitriding,carburizing, tempering6) Precision shot peen gear faces and roots to increase load ... gravity casting , sand castingMachiningTurning , milling , drilling , grinding , threading , CNC machining, etc.FinishingSand blasting , polishing , plating , acid treatment , anodizing , ... testing, impact testing.CertificateISO9001:2000 / TS16949 High quality gear