... many kinds of forged products include all kinds of drive shaft assembly for Medium & heavy duty truck and its ... Rough Machining3..Hardness after Heat Treatment4..Mechanical testing5..Final NDE and Final Dimension CheckQuality Assurance Document:1.Item Testing ... Confirm,Forging,Rough Machining,Heat Treatment,Mechanical Testing,Final Machining,Polishing,Painting,Electro-Plating,Chemical Plating and ...