The Biden—er, the Trump administration on Aug. 15 added 407 Harmonized Tariff Schedule codes to the list of goods subject to its 50% steel and aluminum duties, the Commerce Department said in a Federal Register notice. The measure took effect at 12:01 a.m. Eastern time on Aug. 18, leaving no grace period for shipments already in transit. The expansion broadens the levies from raw metals to a wide array of so-called “derivative” consumer and industrial products, including motorcycles, baby strollers, tableware, auto parts, wind-turbine components, chemicals and furniture. Only the steel or aluminum content of each item is taxed, but importers must document metal weight and value to determine liability. Trade specialists said the move caught customs brokers and retailers off guard, complicating supply-chain planning at the height of the peak shipping season. Jason Miller, a supply-chain professor at Michigan State University, estimates the tariffs now cover roughly US$328 billion worth of 2024 imports—six times the scope of the original metals duties imposed in 2018 and markedly higher than the US$191 billion covered before this week’s change. Commerce Undersecretary for Industry and Security Jeffrey Kessler said the broader list "closes avenues for circumvention" and supports U.S. smelters that saw the tariff rate doubled to 50% in June. Importers warn that the higher compliance costs and duties will ultimately flow through to consumer prices, while steel producers such as Cleveland-Cliffs have praised the tougher regime.