Detailed Product Description Specifications: Screw diameter: 15mm-300mm L/D Ratio: 10-56 Materials: 38CrMoAlA, ... bimetallic-alloy, Vacuum quenching. Types Of Extruder Screw: Gradient-type, Mutant-type, Wave-type, Shielding-type, Double shielding-type, Conical-type, Shunt-type, Separation-type, Exhaust-type, Pin-type, Mixing-type, etc.