The split is based on cross-sectional shape. If the cross-section is square or rectangular and the width is less than twice the thickness, use 720711. If the cross-section is rectangular and the width is at least twice the thickness (a slab-like shape), use 720712. If the cross-section is neither of those — for example, round or other non-rectangular — use 720719. All three apply only to low-carbon grades; higher-carbon semifinished products go to 720720.

Importers generally require a mill test certificate (MTC) confirming chemical composition and mechanical properties, a commercial invoice with country of origin and HTS classification, and a certificate of origin. For shipments subject to antidumping or countervailing duty orders, a scope ruling or detailed product description may be needed to confirm applicability. A licensed customs broker can advise on current CBP requirements.