7507 Tubes, pipes and tube or pipe fittings `e.g., couplings, elbows, sleeves`, of nickel

7507 (01/1988-..) Tubes, pipes and tube or pipe fittings `e.g., couplings, elbows, sleeves`, of nickel 75071100 (01/1988-..) Tubes and pipes of non-alloy nickel 75071200 (01/1988-..) Tubes and pipes of nickel alloys 75072000 (01/1988-..) Tube or pipe fittings, of nickel