HTS code 8409.99.99 covers "Parts suitable for use solely or principally with the engines of heading 8407 or 8408 › For aircraft engines › Other › Cast-iron parts, not advanced beyond cleaning, and machined only for the removal of fins, gates, sprues and risers or to permit location in finishing machinery › Other" 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.