... > SECTION XV - BASE METALS AND ARTICLES OF BASE METAL > CHAPTER 72 - IRON AND STEEL > IV. OTHER ALLOY STEEL; HOLLOW DRILL BARS AND RODS, OF ALLOY OR NON-ALLOY STEEL > 7228 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 > Bars and rods, of silico-manganese steel > Of rectangular (other than square) cross-section, hot-rolled on four faces