Section 232 metals tariffs are now calculated on the full value paid by U.S. customers rather than the foreign declared import price—a valuation methodology shift that directly impacts how customs software must compute duties on steel, aluminum, and copper articles.
President Trump signed a proclamation establishing a tiered tariff structure: a flat 50% rate applies to articles made entirely or almost entirely of steel, aluminum, or copper. Derivative articles substantially made of these metals face a 25% tariff through 2027. Certain metal-intensive industrial and electrical grid equipment carries a 15% rate, while products manufactured abroad using entirely American-sourced steel, aluminum, or copper are subject to a reduced 10% tariff.
Key threshold for compliance teams: Products containing 15% or less steel, aluminum, or copper content are now exempt from Section 232 metals tariffs entirely. Systems must accurately track metal content percentages to apply this exemption correctly.
The valuation change targets a specific compliance gap. According to The White House, some metals importers have claimed artificially lower import values to reduce tariff exposure. By shifting the assessment basis to prices paid by U.S. customers, the proclamation closes this arbitrage opportunity and captures the full value of covered imports.
API and rate cache implications: Trade compliance systems pulling HTS data must now account for dual valuation scenarios—the traditional declared value and the U.S. customer price. Rate lookups for steel, aluminum, and copper classifications require logic to determine which tier applies based on metal composition thresholds (100%, substantial, 15% or less).
The proclamation builds on Trump's June 2025 increase of steel and aluminum tariff rates to 50% and his July 2025 addition of copper to the Section 232 regime. Earlier in February 2025, Trump eliminated country-specific and product exemptions that had accumulated during the Biden administration.
Industry capacity data cited in the proclamation shows domestic steel mill utilization at approximately 77.2%, up from 72.3% in 2017. Aluminum capacity utilization stands at roughly 50.4%, compared to 39% in 2017. The Commerce Secretary's stated goal is sustained 80% utilization across both industries.
The American Iron and Steel Institute endorsed the changes, with AISI President Kevin Dempsey noting the measures "simplify the process for applying the steel tariffs to critical steel derivative products." New domestic capacity is projected to expand, with over four million tons of crude steelmaking capacity expected online within two years across Arkansas, South Carolina, and West Virginia, plus aluminum smelter construction in Oklahoma.
For engineering teams maintaining tariff calculation engines, the 2027 sunset on the 25% derivative rate and the 15% content exemption threshold represent critical parameters requiring systematic tracking and validation against source HTS classifications.
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