Section XVI · Nuclear reactors, boilers, machinery and mechanical appliances; parts

8431.20

Of machinery of heading 8427

How this code is built
84

Chapter

Nuclear reactors, boilers, machinery and mechanical appliances; parts

31

Heading

The product family within the chapter

20

Subheading

The specific good, identical worldwide

The first six digits are the same in every country that uses the Harmonized System. The United States adds two more for the tariff rate and, often, two more for statistics — which is why the rates below are listed against 8- and 10-digit numbers rather than against this code.

How the schedule reaches this code

  1. 84Nuclear reactors, boilers, machinery and mechanical appliances; parts
  2. 8431Parts suitable for use solely or principally with the machinery of headings 8425 to 8430:
  3. Of machinery of heading 8427

Published US duty rates

Duty is set at the 8- or 10-digit line, not at this 6-digit subheading, so more than one rate can sit under this code.

  • 8431.20.00.00Of machinery of heading 8427No.
    General
    Free
    Special (FTA)
    —

    No preferential rate published.

    Column 2
    35%

    Countries without normal trade relations.

Schedule footnotes

  • See 9903.88.01.
  • See 9903.88.69.

A reference to Chapter 99 means an additional action — a Section 232 or 301 measure, an exclusion, or a quota — applies on top of the rate above.

This is the listed rate. Antidumping and countervailing duty orders, Chapter 99 actions and preference qualification all change what is actually collected, and classification is a judgement about your goods. Verify with your licensed customs broker before you file.

Other subheadings in heading 8431

Source: U.S. International Trade Commission (USITC) — 2026 HTS Revision 12, released 2026-07-21, published at hts.usitc.gov. A U.S. Government work in the public domain.