Section 15 BASE METALS AND ARTICLES OF BASE METAL 73 ARTICLES OF IRON OR STEEL 73 05 406.4 MM, OF IRON OR STEEL. 73 05 12 OTHER LINE PIPE USED FOR OIL/GAS PIPELINES, LONGITUDINALLY WELDED Commodity Code Description 73 05 12 00 OTHER LINE PIPE USED FOR OIL/GAS PIPELINES, LONGITUDINALLY WELDED