Bimetallic Conical Twin Screw&Barrel 1.38CrMoALA,SACM645 2.Optimum performance 3.wearproof/corrosion proof 4.more lifspan Specifications of standard for 55/110 conical double screw and cylinder for pvc extruder machine: 45/97,51/105, 55/110, 65/132, 80/156, 80/172, 92/188. Advantages of 92/188 conical double screw and cylinder for pvc extruder machine: 1.Advanced Nitriding Technology 2.Anti- ...