6791: Tubes, pipes & hollow profile, seamless, iron, steel

67911: Tubes, pipes & hollow profiles, of cast iron 67912: Line pipe (excludingcast iron) for oil or gas pipelin. 67913: Casing, tubing & drill pipes, for oil or gas 67914: Other tubes, pipes, circ. cross-sect., non-all. steel 67915: Other tubes, pipes, circ. cross-sect., stainle. steel 67916: Other tubes, pipes, circ. cross-sec., other alloy st. 67917: Other seamless tubes, pipes and hollow profiles 6791: Tubes, pipes & hollow profile, seamless, iron, steel