President Donald Trump on Monday adjusted tariffs on certain steel, aluminum and copper imports, notably lowering rates for farming equipment and expanding categories for industrial machinery.An executive order reduced tariffs on agricultural equipment, including combines and harvesters, and HVAC systems, from 25 percent to 15 percent. The 15 percent tariff category for industrial equipment was also expanded to encompass mobile machinery like bulldozers and forklifts, provided they are imported from countries with U.S. trade deals.Furthermore, a 10 percent duty rate was introduced for nations using at least 85 percent melted and poured or smelted and cast steel or aluminum by weight, a move designed to promote the use of U.S. metals.Tariffs on copper, steel and aluminum were imposed during Trump's first term in 2018 (Jacquelyn Martin/AP)The changes go into effect Monday. They are temporary and set to expire at the end of 2027.“In my judgment, this temporary modification appropriately accounts for these products’ roles in productive economic activity in the United States,” Trump said in his order.Tariffs on copper, steel and aluminum were imposed during Trump's first term in 2018 under Section 232 of Trade Expansion Act of 1962 — which allows tariffs on imports that are deemed a threat to national security. He renewed those tariffs in April 2025.Since then, Trump has been adjusting tariffs on metals and metal products. In June 2025, he hiked nearly all of his tariffs on steel and aluminum imports to a punishing 50 percent from 25 percent.In April 2026, he set a flat 50 percent rate for goods made entirely or almost entirely of aluminum, steel, or copper — such as steel coils or aluminum sheet — while implementing a 25 percent tariff rate for derivative products made “substantially” of steel, aluminum or copper.Barry Appleton, a law professor and co-director New York Law School’s Center for International Law, said the adjustments appear to be more about the midterm elections than true relief for farmers."Farm bankruptcies are soaring, farm sentiment is declining, and Republican senators are openly warning their party is heading toward midterm losses in key agricultural states," he said. “This proclamation is the White House’s response: throw the farm belt a bone before voters go to the polls.”