CBP generally treats the country where substantial transformation occurs — the smelting or refining country — as the country of origin for refined metals. This means a copper cathode smelted in one country from ore mined in another will carry the origin of the smelting country, which determines applicable MFN duty rates and whether any antidumping or countervailing duty orders apply.

Section 232 tariffs were primarily applied to steel and aluminum articles. Other nonferrous metals such as copper, zinc, and nickel are not currently subject to Section 232 measures, though they may be subject to antidumping or countervailing duty orders on specific product forms from specific origins. Importers should verify the current trade-remedy landscape for each metal and supplier country.