HTS code 5006.00.10.00 covers "Silk yarn and yarn spun from silk waste, put up for retail sale; silkworm gut › Containing 85 percent or more by weight of silk or silk waste" 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.