parallel twin screw and double hole cylinder: Φ 35/35- Φ 250/250 L/D ratio:16-35 The compression ratioof screws can be desighed acording to dofferent produts andingrediens. . base materials: 38 CrMoAIA(JIS SACM645), 42CrMo(AISI4140), 9Cr18MoV, CW6Mo5Cr4V2, SKD61ect. bimetallic alloy maerials: Fe-based alloy, Ni-based alloy, Co-based alloy, NiCo-based alloy, Tungsten carbide Heat-treatment Nitriding treatment, Electroplate hard-chrome, High-frequency quenching, Spraying corrosion wear-resisting dual metal layers, Vacuum quenching