Section 15 BASE METALS AND ARTICLES OF BASE METAL 74 COPPER AND ARTICLES THEREOF 74 11 COPPER TUBES AND PIPES. 74 11 22 TUBES & PIPES OF COPPER-NICKEL/COPPER-NICKEL-ZINC BASE ALLOYS Commodity Code Description 74 11 22 00 TUBES & PIPES OF COPPER-NICKEL/COPPER-NICKEL-ZINC BASE ALLOYS