1.zf gearbox for single screw extruder machine 2.HRC54-62,hard ... by carburization, quenching and tooth grinding processZLYJ112,133,146,173,200,225,250,280,315,330,375,420,450;ZSYJ315,375 ... . Stocked products are available, please contact me for further informaiton . zf gearbox for single screw extruder machine