The HTS chapter notes define unalloyed aluminum as material in which no single alloying element exceeds a specified weight percentage threshold (generally 99% minimum aluminum content, with limits on individual alloying additions). If silicon, copper, magnesium, or other elements are present above those thresholds, the material classifies as an alloy under 68412. Mill certificates showing the chemical composition are essential for making this determination at entry.

Section 232 product exclusions are granted on a product-specific and sometimes requester-specific basis by the Department of Commerce. An exclusion covers a defined product description (including alloy designation, form, and dimensions) and may be limited to a specific volume or time period. Importers should check the current exclusion registry and ensure their product description matches the exclusion exactly before claiming relief, as a mismatch can result in retroactive duty liability.