HTS code 7305.20.20.00 covers "Other tubes and pipes (for example, welded, riveted or similarly closed), having circular cross sections, the external diameter of which exceeds 406.4 mm, of iron or steel › Casing of a kind used in drilling for oil or gas › Threaded or coupled" under the US Harmonized Tariff Schedule. This is the official duty rate charged by US Customs when this product is imported into the United States, sourced directly from the U.S. International Trade Commission and refreshed daily.