# HS code 8421.91: Parts, of centrifuges, including centrifugal dryers > HS code 8421.91 covers parts, of centrifuges, including centrifugal dryers. It sits in heading 84.21 (centrifuges, including centrifugal dryers; filtering or purifying machinery and apparatus, for liquids or gases) in chapter 84 (nuclear reactors, boilers, machinery and mechanical appliances; parts thereof). Other goods of heading 84.21 are classified under 8421.11 (centrifuges, including centrifugal dryers, cream separators), 8421.12 (centrifuges, including centrifugal dryers, clothes-dryers), 8421.19 (centrifuges, including centrifugal dryers, other), 8421.21 (filtering or purifying machinery and apparatus for liquids, for filtering or purifying water) or 7 others. National tariff lines under 8421.91 are live on border.bot for the United States (3 lines, also used by 1 other country). Source: https://border.bot/hs-codes/842191 Last updated: 11 October 2026 [HS codes](https://border.bot/hs-codes) / [Chapter 84](https://border.bot/hs-codes/84) / [84.21](https://border.bot/hs-codes/8421) / [8421.91](https://border.bot/hs-codes/842191) ## Key facts - HS code: 8421.91 - Covers: Parts, of centrifuges, including centrifugal dryers - Heading: [84.21: Centrifuges, including centrifugal dryers; filtering or purifying machinery and apparatus, for liquids or gases](https://border.bot/hs-codes/8421) - Chapter: [84: Nuclear reactors, boilers, machinery and mechanical appliances; parts thereof](https://border.bot/hs-codes/84) - Edition: HS2022 - Duty in the United States: [See its 3 lines](https://border.bot/countries/united-states/hs-codes/842191) ## What this code covers HS code 8421.91 covers parts, of centrifuges, including centrifugal dryers. The legal text of the subheading is “Parts: Of centrifuges, including centrifugal dryers”, read under “Parts”, in HS2022. ## What it doesn’t cover Other goods of heading 84.21 are classified under 8421.11 (centrifuges, including centrifugal dryers, cream separators), 8421.12 (centrifuges, including centrifugal dryers, clothes-dryers), 8421.19 (centrifuges, including centrifugal dryers, other), 8421.21 (filtering or purifying machinery and apparatus for liquids, for filtering or purifying water) or 7 others. - [8421.11](https://border.bot/hs-codes/842111) Centrifuges, including centrifugal dryers: Cream separators - [8421.12](https://border.bot/hs-codes/842112) Centrifuges, including centrifugal dryers: Clothes-dryers - [8421.19](https://border.bot/hs-codes/842119) Centrifuges, including centrifugal dryers: Other - [8421.21](https://border.bot/hs-codes/842121) Filtering or purifying machinery and apparatus for liquids: For filtering or purifying water - [8421.22](https://border.bot/hs-codes/842122) Filtering or purifying machinery and apparatus for liquids: For filtering or purifying beverages other than water - [8421.23](https://border.bot/hs-codes/842123) Filtering or purifying machinery and apparatus for liquids: Oil or petrol-filters for internal combustion engines - [8421.29](https://border.bot/hs-codes/842129) Filtering or purifying machinery and apparatus for liquids: Other - [8421.31](https://border.bot/hs-codes/842131) Filtering or purifying machinery and apparatus for gases: Intake air filters for internal combustion engines - [8421.32](https://border.bot/hs-codes/842132) Filtering or purifying machinery and apparatus for gases: Catalytic converters or particulate filters, whether or not combined, for purifying or filtering exhaust gases from internal combustion engines - [8421.39](https://border.bot/hs-codes/842139) Filtering or purifying machinery and apparatus for gases: Other - [8421.99](https://border.bot/hs-codes/842199) Parts: Other ## How it is structured 8421.91 is a six-digit subheading. Its first two digits, 84, are the chapter; the first four, 8421, are heading 84.21; the last two, 91, identify the subheading within the heading. Countries add their own digits after these six for their national tariff lines. - Chapter 84: Nuclear reactors, boilers, machinery and mechanical appliances; parts thereof - Heading 84.21: Centrifuges, including centrifugal dryers; filtering or purifying machinery and apparatus, for liquids or gases - Within the heading: Parts - Subheading 8421.91: Of centrifuges, including centrifugal dryers ## In other countries National tariff lines under 8421.91 are live on border.bot for the United States (3 lines, also used by 1 other country). - [United States](https://border.bot/countries/united-states/hs-codes/842191): 3 lines, used by 1 other country - Previous subheading: [8421.39](https://border.bot/hs-codes/842139) Filtering or purifying machinery and apparatus for gases: Other - Next subheading: [8421.99](https://border.bot/hs-codes/842199) Parts: Other ## Frequently asked questions ### What does HS code 8421.91 cover? HS code 8421.91 covers parts, of centrifuges, including centrifugal dryers. ### Which heading and chapter is HS code 8421.91 in? HS code 8421.91 is in heading 84.21 (centrifuges, including centrifugal dryers; filtering or purifying machinery and apparatus, for liquids or gases) in chapter 84 (nuclear reactors, boilers, machinery and mechanical appliances; parts thereof). ### Where are goods of heading 84.21 classified when 8421.91 doesn’t fit? Other goods of heading 84.21 are classified under 8421.11 (centrifuges, including centrifugal dryers, cream separators), 8421.12 (centrifuges, including centrifugal dryers, clothes-dryers), 8421.19 (centrifuges, including centrifugal dryers, other), 8421.21 (filtering or purifying machinery and apparatus for liquids, for filtering or purifying water) or 7 others. ### Which countries’ tariffs list national lines under HS code 8421.91? National tariff lines under 8421.91 are live on border.bot for the United States (3 lines, also used by 1 other country). ## Sources and updates The Harmonized System legal text comes from border.bot release 2 (edition HS 2022), imported from a file, and has been live since 11 October 2026. This page was last updated on 11 October 2026. Guidance from published tariff data, not a binding ruling. For a decision customs must follow, apply to the destination’s customs authority for a binding tariff ruling. Machine-readable: https://border.bot/hs-codes/842191.json