... 38CrMoAi 2.HV above 900 3.special designed,high strength 4.CE High quality conical twin screw barrel: Our company,Shanghai ... designed and produced by ourselves,with high quality and well performance.Our products include all types of plastic extruder,pelletizing machine, ... screw and barrel have the advantages of advanced design,high output,low energy consumption,good plasticization,long life service ...