Executive Summary

  • President Trump's April 2 proclamation restructures Section 232 tariffs, imposing 50% duties on products made entirely of steel, aluminum, or copper and 25% on derivative articles — calculated on full customs value rather than metal content alone.
  • The shift to full-value tariffs on derivative products represents a significant cost increase for American manufacturers who import metal-containing components, transforming Section 232 into a content-based metals tariff regime.
  • The same proclamation imposed tariffs of up to 100% on patented pharmaceutical imports and 50% secondary tariffs on nations supplying Iran with weapons.
  • The restructured tariffs represent the administration's pivot after the Supreme Court's IEEPA ruling, maximizing authority under statutes the Court has not yet challenged.

On April 2, President Trump signed a proclamation fundamentally restructuring Section 232 tariffs on steel, aluminum, and copper imports. The changes took effect on April 6 at 12:01 a.m. EDT, and they represent the most significant overhaul of American metals trade policy since the original Section 232 tariffs were imposed in 2018.

The new framework replaces the previous system — which calculated tariffs on derivative products by splitting the customs value between metal and non-metal content — with a simpler but steeper approach based on total metal content by weight.

The New Rate Structure

Under the revised framework, articles made entirely or almost entirely of aluminum, steel, or copper are now subject to a flat 50% tariff on their full customs value. Derivative articles that are substantially made of these metals but include other materials face a 25% tariff on the full value of the imported product. Products containing 15% or less metal content by weight are exempt from Section 232 tariffs entirely.

There is a reduced rate for products where the steel, aluminum, or copper content was entirely melted, poured, smelted, or cast in the United States — those face a 10% tariff. This provision is designed to incentivize domestic sourcing of raw materials even in imported finished goods.

The United Kingdom received a partial carve-out: UK steel and aluminum products that would otherwise face the 50% tariff will instead pay 25%, and those that would otherwise face 25% will pay 15%.

What This Means for American Manufacturers

The shift to full-value tariffs on derivative products is the most consequential change. Under the previous system, an imported automobile part made partially of steel might have had tariffs calculated only on the steel content portion. Now, the tariff applies to the full customs value of the product. For manufacturers who import components — engine parts, construction materials, industrial equipment — this represents a significant cost increase.

Trade compliance experts say the new system transforms Section 232 into what is effectively a content-based metals tariff regime. Material percentage and sourcing documentation are now as important as traditional HTS classification. Importers will need to prove exact metal percentages to determine their tariff rate, and whether they qualify for the 15% threshold exclusion or the reduced U.S.-origin rate.

The Sovereignty Argument

The administration frames the restructured tariffs as a national security measure — the same legal basis that has supported Section 232 since its inception. The argument is straightforward: domestic capacity to produce steel, aluminum, and copper is essential to national defense, and tariffs protect that capacity from being hollowed out by cheaper foreign imports.

There is merit to this position. America's steel industry has seen decades of decline driven by subsidized foreign production, particularly from China. Aluminum smelting capacity has similarly eroded. Copper, increasingly critical for defense electronics and energy infrastructure, faces growing supply chain vulnerabilities.

But the tariff restructuring goes beyond protecting raw material production. By applying full-value tariffs to derivative products, the new framework effectively extends protection to downstream manufacturing as well. Whether this creates a more resilient industrial base or simply raises costs for American businesses that depend on imported components is the central policy tension.

The Pharmaceutical Tariff Connection

The same April 2 proclamation that restructured metals tariffs also imposed tariffs of up to 100% on patented pharmaceutical imports under Section 232. While the legal and policy arguments differ, the two actions share a common philosophy: using tariff authority aggressively to reshape supply chains that the administration views as vulnerabilities.

The pharmaceutical tariff is particularly notable because it targets patented drugs — meaning brand-name medications that often have no domestic manufacturing alternative. The administration argues this will incentivize pharmaceutical companies to build production capacity in the United States, but the near-term effect is higher drug costs for American consumers and the healthcare system.

Secondary Tariffs on Iran's Suppliers

The proclamation also included a 50% secondary tariff on any nation supplying Iran with weapons, effective immediately. This measure connects trade policy directly to national security in the most literal sense, using economic leverage to punish countries that arm a hostile regime. It represents an expansion of the secondary sanctions approach that has been a cornerstone of Iran policy across multiple administrations.

Looking Ahead

The restructured Section 232 tariffs are the administration's answer to the Supreme Court's IEEPA ruling. Unable to rely on emergency powers for broad-based tariffs, the executive branch is maximizing its authority under statutes that the Court has not challenged. The question now is whether Section 232 — designed for narrow national security tariffs — can bear the weight of a comprehensive industrial policy. Courts will likely have to answer that question before long.