Section 15 BASE METALS AND ARTICLES OF BASE METAL 74 COPPER AND ARTICLES THEREOF 74 12 COPPER TUBE OR PIPE FITTINGS (FOR EXAMPLE, COUPLINGS ELBOWS, SLEEVES). 74 12 10 TUBE OR PIPE FITTINGS OF REFINED COPPER Commodity Code Description 74 12 10 00 TUBE OR PIPE FITTINGS OF REFINED COPPER