... ,PPR for Plastic Extruder Machine Conical Twin Screw and Barrel Zhejiang Bohai Conical twin screw barrelDiameterΦ25/53,35/77,45/90,51/10,55/110,65/120,65/132 ... ridge,and uses different alloy and welding methods for the screw of different functions.Materials38CrMoAlA (JIS SACM645)SKD61 .etcApplication PS,HIPS,ABS ...