... : bimetallic layer PP,PE,PVC,PET,ABS,PPR for Plastic Extruder Machine Conical Twin Screw and Barrel ... powders being sprayed and welded on the screw's ridge,and uses different alloy and welding ... Materials38CrMoAlA (JIS SACM645)SKD61 .etcApplication PS,HIPS,ABS,SAN,EPN/LDPE,HDPE,UHMPE,EVA,PP,PVC ... 3.5mmWarranty period:2-4years(Depends on the plastic raw materials)Bimetallic: much longer lifetime.Nitriding ...