Heading 8421

Centrifuges, including centrifugal dryers; filtering or purifying machinery and apparatus, for liquids or gases; parts thereof

24 declarable lines

Heading 8421 covers centrifuges and centrifugal dryers, plus machinery that filters or purifies liquids or gases, and parts for that equipment. It splits first by machine type: centrifuges (8421.11 to 8421.19), liquid filters (8421.21 to 8421.29), gas filters (8421.31 to 8421.39), and parts (8421.91 and 8421.99). Most lines in the heading are free of duty, with the main exceptions being certain centrifuge and engine filter lines.

Products in this heading

Cream separators used in dairies
Centrifugal clothes-dryers
Water filtration units for a building or process line
Oil or fuel filters for internal combustion engines
Intake air filters for engines
Catalytic converters and particulate filters for engine exhaust
Dust collection and air purification equipment
Replacement filter parts for water purification machinery

How to choose the right subheading

Whether the machine works on liquids, on gases, or is a centrifuge, since the heading splits on that first.
For centrifuges, the specific use, such as cream separation or drying clothes.
For liquid filters, the fluid handled: water, beverages, oil or fuel, or other liquids.
For gas filters, the application: engine intake air, engine exhaust, dust collection, gas cleaning, or gas separation.
Whether the item is a complete machine or a part, which moves it to 8421.91 or 8421.99.

Often confused with

Pumps for moving liquids
Heading 8421 covers separating or purifying, not moving, liquids.
Heading 8413
Air or gas compressors and fans
Fans and compressors move air; 8421 covers cleaning or separating it.
Heading 8414
Air conditioning machines
A machine that changes temperature and humidity is classified in 8415 even if it includes a filter.
Heading 8415
Milking machines and dairy machinery
Dairy processing equipment belongs to 8434; only cream separators are named in 8421.
Heading 8434
Dishwashing machines
Cleaning machines for dishes are classified in 8422, not as filtering machinery.
Heading 8422

Frequently asked questions

What is the HTS code for an engine intake air filter?

Intake air filters for internal combustion engines are classified under 8421.31.00.00. The general (MFN) rate for that line is 2.5%.

What is the duty on a water purifying filter?

Machinery for filtering or purifying water falls under 8421.21.00.00. The general (MFN) rate is Free.

How do I classify a replacement filter element for a water purification unit?

Parts of machinery for filtering or purifying water go under 8421.99.01.40. The general (MFN) rate for that line is Free, while other parts of heading 8421 machinery go under 8421.99.01.80, also Free.

Guide written from the official schedule text. Rates quoted are general (MFN) rates; check the line page for trade agreement rates and the classification of your exact product.