On June 1, President Trump issued a proclamation further modifying the Section 232 tariff regimes applicable to imports of steel, aluminum, and copper products. The modifications take effect for goods entered for consumption, or withdrawn from warehouse for consumption, on or after 12:01 a.m. EDT on June 8, 2026.

As background, the current Section 232 framework imposes additional duties on certain steel, aluminum, copper, and derivative products based on the administration’s determination that imports of those products threaten to impair U.S. national security. The April 2026 proclamation generally established: (1) a 50% duty on specified metal products; (2) a 25% duty on certain derivative products; and (3) a temporary reduced-duty category for certain fixed industrial machinery and power equipment.

The June 1 proclamation modifies product coverage of the 232 tariffs and specific tariff rates for certain machinery, agricultural equipment, HVAC products, and related parts.

Key Changes

• Expansion of Reduced-Tariff Treatment for Agricultural Equipment and HVAC Products
  The proclamation expands the category of steel and aluminum derivative products eligible for the temporary reduced-duty treatment – 15% – through Dec. 31, 2027. The expanded categories include various agricultural equipment and machinery parts, as well as certain residential HVAC equipment and parts. See Appendix Annex III.
• Special Tariff Treatment for Mobile Industrial Equipment
  The proclamation creates a new tariff treatment framework for mobile industrial equipment and machinery. See Annex I-C. The affected articles include various steel derivative products, including forklifts, lift trucks, bulldozers, graders, scrapers, road rollers, front-end loaders, excavators, non-agricultural tractors, mobile cranes, mobile drilling derricks, and certain parts and attachments for such machinery. For covered products entered between June 8, 2026 and Dec. 31, 2027, the default additional Section 232 duty is 25%. However, lower treatment may apply in circumstances explained below.

1. 1. Listed Country of Origin: For products of Argentina, Ecuador, El Salvador, Guatemala, Japan, the Republic of Korea, Liechtenstein, Switzerland, Taiwan, the United Kingdom, or a member nation of the European Union, the additional Section 232 duty is calculated so that the product’s Column 1 (MFN) duty rate plus the additional Section 232 duty totals 15%. If the Column 1 duty rate is already at least 15%, no additional Section 232 duty is imposed under that clause.
   2. U.S. Origin Metal: For covered derivative articles whose relevant aluminum or steel content is composed of 85% (previously 95%) U.S.-origin metal by weight, the proclamation provides that, if the product’s Column 1 duty rate is below 10%, the additional Section 232 duty is calculated so that the total reaches 10%. And, if the Column 1 duty rate is already at least 10%, no additional duty is due under that provision.
      1. This reduced tariff treatment also applies to the articles classifiable in Chapters 84, 85, or 87 of the HTS and listed in this Annex I-B when used exclusively in the manufacture of agricultural equipment, fixed industrial equipment, or mobile industrial equipment
   3. USMCA Products: For USMCA-qualifying products, the 25% duty applies only to the non-U.S. content of the product, subject to a minimum total effective duty of 15%.

• New Coverage for Aluminum Lithographic Plates and Steel Racks as Derivative Products
  The proclamation also expands the derivative-product coverage by adding aluminum lithographic plates and steel racks. A 25% ad valorem Section 232 tariff shall apply to the full value of the articles. Companies should carefully review the revised annexes to determine whether products previously subject to the standard derivative-product tariffs may now qualify for reduced-duty treatment.

• Special Rule for Certain Parts Used in Covered Equipment
  The proclamation established a new tariff treatment for machinery and mechanical appliances, electrical machinery and equipment, and vehicles and vehicle parts classified in Chapters 84, 85, or 87 of the HTS included in Annex I-B when imported exclusively for use in the manufacturing of mobile industrial equipment listed in Annex I-C to this proclamation, or agricultural equipment or fixed industrial equipment listed in Annex III to this proclamation. The default additional Section 232 duty for these articles is 25%. However, lower treatment may apply in circumstances explained below.

1. 1. For products with a Column 1 duty rate below 15%, the additional Section 232 duty is set so that the combined Column 1 duty and Section 232 duty equals 15%. For products with a Column 1 duty rate of at least 15%, the additional Section 232 duty is zero.
   2. A lower 10% tariff rate applies where the derivative article’s aluminum or steel content is composed of 85% (previously 95%) U.S.-smelted/cast or U.S.-melted/poured, respectively.

• Domestic Metal-Content Threshold Reduced from 95% to 85%
  The proclamation lowers the threshold for determining whether a product’s metal content is treated as composed entirely of U.S.-origin aluminum, steel, or copper from 95% to 85%. In addition to the effects discussed above regarding products covered in Annex I-C of this proclamation, this change also applies to a large number of aluminum, steel, and copper articles included in Annexes I-A&B of the April proclamation.