Section 15 Base metals and articles of base metal 74 Copper and articles thereof 74 11 Copper tubes and pipes 74 11 22 - - Of copper-nickel base alloys (cupro-nickel) or copper-nickel-zinc base alloys (nickel silver) Commodity Code Description 74 11 22 00 - - Of copper-nickel base alloys (cupro-nickel) or copper-nickel-zinc base alloys (nickel silver)