The 4.75 mm threshold is a defined classification break that separates heavy-gauge hot-rolled stainless coil (67531) from intermediate and thin hot-rolled stainless coil categories. Products at or above 4.75 mm thick fall in this heading; thinner products fall in the 67532 or 67533 headings depending on whether they are 3 mm or more but under 4.75 mm, or under 3 mm. Thickness is measured at the thinnest point of the coil, and mill certificates should confirm the nominal and minimum thickness to support classification.

The US has maintained antidumping and countervailing duty orders on stainless steel products from multiple countries. Importers of hot-rolled stainless coil should verify whether current orders cover the specific grade, thickness, and country of origin of their product, and whether any scope rulings or exclusions apply. Section 232 tariffs also apply unless a product-specific exclusion has been granted. Consulting a licensed customs broker before contracting is advisable.