We supply various types of screw barrels according to customer's requirement. Product name: screw barrel for PVC,PE,PP machine / novel type screw barrel Key word:screw barrel,bimetallic screw barrel,extruder screw barrel,screw barrel for injection molding machine,conical or parallel screw barrel, Material:38CrMoAlA,SKD11,SKD61,HPT2B,high quality alloy steel,etc Technology:nitriding treatment,alloy coating sparying,heat-treatment,etc Appliance:PE,PVC,PP,etc Technical index: Depth of Nitrated Layer: 0.5-0.8mm Hardness of nitration: 900-1020Hv Fragility of nitration: Less than grade 1 Surface roughness: Ra 0.4um Hardness of Cr-coating Layer: ≥950Hv Thickness of Cr-coated Layer: 0.03-0.08mm Hardness of Bimetallic Layer: HRC55-72 Depth of Bimetallic Layer: >2mm Guarantee:Common nitrided:1-2years,Bimetallic:much long time...