PP,PE,PVC,PET,ABS,PPR for Plastic Extruder Machine Conical Twin Screw and Barrel material: bimetallic layer PP,PE,PVC, ... PET,ABS,PPR for Plastic Extruder Machine Conical Twin Screw and Barrel Zhejiang Bohai Conical twin screw barrelDiameterΦ25/53,35/77 ... Nitriding treatment 2)special anti-wear & abrasion alloy (bimetallic)3)tungsten carbide;4)cobalt base alloy5)stainless steel 6)Gh113 nickel ...