Section 15 Base metals and articles of base metal 72 Iron and steel 72 28 Other bars and rods of other alloy steel; angles, shapes and sections, of other alloy steel; hollow drill bars and rods, of alloy or non-alloy steel 72 28 20 - Bars and rods, of silico-manganese steel Commodity Code Description 72 28 20 00 - Bars and rods, of silico-manganese steel