... > SECTION XV - BASE METALS AND ARTICLES OF BASE METAL > CHAPTER 73 - ARTICLES OF IRON OR STEEL > 7306 Other tubes, pipes and hollow profiles (for example, open seam or welded, riveted or similarly closed), of iron or steel > Other, welded, of circular cross-section, of iron or non-alloy steel > Other > Threaded or threadable tubes (gas pipe) > Plated or coated with zinc