Abrasion-resistant Single Screw Barrel for Beier Diameter 55mm-200mm Min.Order 1 set Materials 38CrMoAIA SKD 61 GH113 Discount Available Application PE.PP.LLDPE,PO Film for Food Package Payment Term T/T, L/C Technical Process 1.Rough Machining 2.Quenching and Tempering 3.Finish Machining 4.Nitriding 5.Screw polishing Technological Parameter Roughness Ra 0.4um Hardness of Quenching and Tempering HB 240-280 Depth of Nitride Layer 0.5~0.8mm ...