Section 15 BASE METALS AND ARTICLES OF BASE METAL 73 ARTICLES OF IRON OR STEEL 73 22 THEREOF, OF IRON OR STEEL. 73 22 90 OTHER AIR HEATERS & HOT AIR DISTRIBUTORS..&PARTS THEREOF, OF IRON/STEEL Commodity Code Description 73 22 90 00 OTHER AIR HEATERS & HOT AIR DISTRIBUTORS..&PARTS THEREOF, OF IRON/STEEL