# United States tariff lines under HS 8540.79

> The United States tariff splits HS 8540.79 (microwave tubes (for example, magnetrons, klystrons, travelling-wave tubes, carcinotrons), excluding grid-controlled tubes: Other) into 2 national lines: 8540.79.10.00 (klystrons) and 8540.79.20.00 (other). The general (MFN) duty differs by line: 3.3% on 8540.79.10.00 and 3.7% on 8540.79.20.00.

Source: https://border.bot/countries/united-states/hs-codes/854079
Last updated: 9 October 2026

[Countries](https://border.bot/countries) / [United States](https://border.bot/countries/united-states) / [Chapter 85](https://border.bot/countries/united-states/hs-codes/85) / [8540.79](https://border.bot/countries/united-states/hs-codes/854079)

## Key facts

- HS subheading: [8540.79](https://border.bot/hs-codes/854079)
- National lines: 2
- Tariff: [United States](https://border.bot/countries/united-states)
- Chapter: 85: Electrical machinery and equipment and parts thereof; sound recorders and reproducers, television image and sound recorders and reproducers, and parts and accessories of such articles

## United States lines under 8540.79

The United States tariff splits HS 8540.79 (microwave tubes (for example, magnetrons, klystrons, travelling-wave tubes, carcinotrons), excluding grid-controlled tubes: Other) into 2 national lines: 8540.79.10.00 (klystrons) and 8540.79.20.00 (other).

The general (MFN) duty differs by line: 3.3% on 8540.79.10.00 and 3.7% on 8540.79.20.00.

- [8540.79.10.00](https://border.bot/countries/united-states/hs-codes/8540791000) Microwave tubes (for example, magnetrons, klystrons, traveling wave tubes, carcinotrons), excluding grid-controlled tubes, Other, Klystrons. Duty (MFN): 3.3%
- [8540.79.20.00](https://border.bot/countries/united-states/hs-codes/8540792000) Microwave tubes (for example, magnetrons, klystrons, traveling wave tubes, carcinotrons), excluding grid-controlled tubes, Other, Other. Duty (MFN): 3.7%

## In other countries

No other national tariff on border.bot has live lines under 8540.79 yet.

- [The Harmonized System text for 8540.79](https://border.bot/hs-codes/854079)

- Previous subheading: [8540.71](https://border.bot/countries/united-states/hs-codes/854071) Magnetrons
- Next subheading: [8540.81](https://border.bot/countries/united-states/hs-codes/854081) Thermionic, cold cathode or photocathode tubes (for example, vacuum or vapor or gas filled tubes, mercury arc rectifying tubes, cathode-ray tubes, television camera tubes); parts thereof

## Frequently asked questions

### How many national tariff lines does the United States tariff have under HS 8540.79?

The United States tariff splits HS 8540.79 (microwave tubes (for example, magnetrons, klystrons, travelling-wave tubes, carcinotrons), excluding grid-controlled tubes: Other) into 2 national lines: 8540.79.10.00 (klystrons) and 8540.79.20.00 (other).

### What is the duty on HS 8540.79 in the United States?

The general (MFN) duty differs by line: 3.3% on 8540.79.10.00 and 3.7% on 8540.79.20.00.

## Sources and updates

The tariff lines for the United States come from border.bot release 1 (edition 2026HTSRev21), read from the publisher’s files, and have been live since 9 October 2026.

The duty rates for the United States come from border.bot release 1 (edition 2026HTSRev21), read from the publisher’s files, and have been live since 9 October 2026.

The trade programmes for the United States come from border.bot release 1 (edition 2026HTSRev21), read from the publisher’s files, and have been live since 9 October 2026.

This page was last updated on 9 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.

Official source files:

- https://hts.usitc.gov/reststop/exportList?from=0000000000&to=9999999999&format=CSV&styles=false

Machine-readable: https://border.bot/countries/united-states/hs-codes/854079.json