When a coated abrasive has a composite backing, classification follows the backing material that imparts the essential character. A disc where the paper layer is the primary structural element goes under 680520, while one where the fabric reinforcement is structurally dominant goes under 680510. If the backing is a non-woven or vulcanized fiber material, 680530 applies. Importers with ambiguous composite constructions should seek a CBP binding ruling.

Coated abrasives originating in Mexico and meeting USMCA rules of origin qualify for preferential tariff treatment under the United States-Mexico-Canada Agreement. Given that Mexico is a leading supplier of these products, verifying USMCA origin qualification — including the applicable tariff-shift rule and any regional-value-content requirement — is a routine step for importers sourcing from Mexican manufacturers.