Detailed Product Description Plastic twin conical screws extruder :1.Material:38CrMoAlA Nitriding treatment, Surface hardness:HV≥900 Nitriding depth:0.5-0.8mm2.Base material:38CrMoAlA ,Special alloy is welded on the flight of screw ,prolong life of screw3.Easy wearing parts of barrel made form anti-wear ally can be improved abrasion preformance .