Conical Twin Screw and Barrel/Cylinder Size: According to the customer demands to make the goods. Base Raw Material for screw :38CrMoAlA, A grade, Special alloy ... , SACM645, 40Cr, AISI4140, 42CrMo Bimetallic of the inner hole centrifugal casting GHII3 nature hard after high temperature Twin Screw and Barrel for Plastic Plate&Sheet -011