From whitehouse.gov

Today, President Donald J. Trump signed a Proclamation to strengthen tariffs imposed on imported steel, aluminum, and copper in order to more effectively address the national-security threat posed by such imports. The Proclamation defines the way that tariffs are assessed, ensuring that they reflect the full value of imported steel, aluminum, and copper products—not an artificially low foreign price. The Proclamation also establishes clear rules for calculating Section 232 metals tariffs. Articles made entirely or almost entirely of aluminum, steel, or copper will pay a flat 50% on their full value — for example, ... (full story)