HTS Code 7610-Structures and parts of structures "e.g., bridges and bridge-sections, towers, lattice masts, pillars and columns, roofs, roofing frameworks, doors and windows and their frames and thresholds for doors, shutters, balustrades", of aluminium (excluding prefabricated buildings of heading 9406); plates, rods, profiles, tubes and the like, prepared for use in structures, of aluminium