Section 15 BASE METALS AND ARTICLES OF BASE METAL 83 MISCELLANEOUS ARTICLES OF BASE METAL. 83 07 FLEXIBLE TUBING OF BASE METAL, WITH OR WITHOUT FITTINGS. 83 07 10 FLEXIBLE TUBING OF BASE METAL,WITH/WITHOUT FITTINGS OF IRON/STEEL Commodity Code Description 83 07 10 00 FLEXIBLE TUBING OF BASE METAL,WITH/WITHOUT FITTINGS OF IRON/STEEL