On May 31, 2018, President Trump signed Proclamation 10712, imposing a 10 percent tariff on all aluminum imports entering the United States, with carve-outs granted to Canada and Mexico. The proclamation invoked national security authority under Section 232 of the Trade Expansion Act of 1962, the same statutory mechanism that had been used weeks earlier for steel tariffs. The tariff applied comprehensively to aluminum products across all categories and sectors, from raw ingots to finished goods used in manufacturing.

The direct effects rippled through multiple segments of the American economy. Manufacturers dependent on aluminum inputs—including aerospace suppliers, automotive producers, beverage container manufacturers, and construction companies—faced immediate cost increases on raw materials. These elevated production costs were frequently passed to consumers through higher prices on everything from canned beverages to aircraft components. Trading partners including the European Union, Canada, Japan, and others responded with retaliatory tariffs targeting American agricultural exports, industrial goods, and consumer products, creating cascading economic pressures across multiple sectors.

This action represented an escalation in the Trump administration's broader trade strategy that would characterize the entire administration and extend into subsequent years, as evidenced by the continuation of national emergency declarations on trade deficits into 2026. Proclamation 10712 was part of a coordinated tariff campaign that preceded other metal tariffs and eventually expanded into broader trade actions. Unlike the later executive order from February 2026 that terminated certain tariff actions, this 2018 proclamation established baseline protectionist policies that would shape American trade relationships for years.

The aluminum tariff faced limited legal challenges compared to other trade actions, though business groups and affected industries mounted significant opposition through administrative and political channels. Congress largely deferred to executive trade authority under the statutory framework, reflecting the broad discretion granted to presidents in Section 232 authority. Substantive reversal would require either executive action to rescind the proclamation or legislative intervention to curtail presidential trade powers, neither of which occurred during or immediately following the Trump administration's tenure.