Twin ParallelBimetallic Screw Barreltwin parallel screw barrel,screw barrel,bimetallic screw barrel,extruder Machinery screw barrel,Plastic Machinerycomponents,twin counter rotationg screws barrelsMaterial: 38CrMoALA(JIS SCM645), W6Mo5Cr4V2, GH113, EN41B, 9Cr18MoV, 42CrMo(JIS SCM440), SKD61,...