NAICS 3279 is a domestic industry classification, not a tariff code. When importing, each product must be classified under the appropriate HTS chapter — for example, Chapter 68 for stone articles or Chapter 70 for glass — and the applicable duty rates and trade-remedy measures are determined at the HTS level, not the NAICS level.

Several product lines within NAICS 3279 — particularly cut stone, abrasives, and mineral wool — have historically been subject to antidumping or Section 301 measures depending on origin. Importers should verify current trade-remedy orders at the HTS line level before sourcing, as coverage and scope vary significantly by product and country.