Standard I-beams (with tapered flanges) fall under 721632, while H-sections (wide-flange beams with parallel flanges) go under 721633, both for hot-worked products 80 mm or more in height. The flange geometry and the mill's own designation on the test certificate are the key distinguishing factors.

Cold-formed sections produced from flat-rolled strip are covered by 721661 and 721691 within heading 7216, so light-gauge steel framing studs and tracks typically classify here. However, if the profile is further processed into a finished article (such as a complete framing assembly), classification may shift to a more specific finished-goods heading.