Section 15 BASE METALS AND ARTICLES OF BASE METAL 72 Iron and steel 72 12 Flat-rolled products of iron or non-alloy steel, of a width of less than 600 mm, 72 12 20 Roofing sheets 72 12 20 10 Roofing sheets Commodity Code Description 72 12 20 10 00 - Electrolytically plated or coated with zinc