High quality zinc alloy Circle screw pressure die casting molding parts. Customized mold cavities design can be provided according to the EAU annual requirements. The outside screw can be formed from mold and do not need to CNC on the secondary machining process that can lowdown the cost. The surface treatment can be design as your requirement. This screw circle casting housing finished with Nickle plating, which pass 48H to 96H salt spray test.