A June 1, 2026 proclamation marks the most consequential restructuring of the Section 232 metals tariffs since they were doubled to 50 percent last year. The headline move cuts the rate from 25 percent to 15 percent on certain HVAC equipment, agricultural machinery such as combines and harvesters, and mobile industrial equipment, with the reduced rate running through December 31, 2027, after which products revert to standard rates. But the structural changes matter more to importers than the rate cut itself. Duties on affected derivative articles now apply to the full customs value of the import rather than to the steel, aluminum, or copper content alone, a shift that ends the content-valuation methodology that had caused widespread compliance confusion since June 2025. At the same time, goods made of 15 percent or less metal content are removed from Section 232 entirely, a genuine exemption that eliminates exposure for a meaningful slice of mixed-material products.
For buyers, the actionable detail sits in the new rate structure. Under the new Annex I-C framework, the standard rate is 25 percent, but lower rates are available for USMCA-qualifying goods from Canada and Mexico, for imports from trade-deal countries, and for products made with at least 85 percent U.S.-melted or smelted metal. For USMCA-qualifying products, the 25 percent rate applies only to non-U.S. content, though total Section 232 exposure cannot fall below 15 percent. The proclamation also expanded the derivative list, adding aluminum lithographic plates and steel racks. All changes take effect June 8, 2026. The combined effect rewards domestic content and verifiable supply chains while raising the stakes on documentation: the difference between the 25 percent floor and the lower tiers now turns on melt origin and qualification status that importers will need to prove at entry.