... shaft 2,material:carbon steel, stainless steel,alloy steel,duplex steel 3,certificate:ISO9001: 2000 ,GL steel gear shaft specificationOEM and Customized service offered Materials: carbon steel, stainless steel,alloy steel,duplex steel ... : 100% ultrasonic test according to EN10228-3, SA388 etc. Process: Forging – Normalizing & Tempering – Proof Machining- Quenching & Tempering – Precision Machining -- ...