Rubber pin cold feed screw and barrel Diameter 60mm-120mm Min.Order 1 set Materials 38CrMoAIA 42CrMo(JIS SCM440) 9Cr18MoV CW6Mo5Cr4V2 Discount Available Application PVC ,CPVC,UPVC 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 ...