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 ... (bimetallic)3)tungsten carbide;4)cobalt base alloy5)stainless steel 6)Gh113 nickel based alloy Nitride Hardness950-1050HVPackingWrapped up by film ...