United States tariff line 8540.99.40.00: Electron guns; radio frequency (RF) interaction structures for microwave tubes of subheadings 8540.71 through 8540.79, inclusive
Last updated
Key facts
- Tariff line
- 8540.99.40.00
- Covers
- Parts, electron guns; radio frequency (RF) interaction structures for microwave tubes of subheadings 8540.71 through 8540.79, inclusive
- Duty (MFN)
- Free
- Additional duties
- None recorded
- Restrictions
- None recorded
- Tariff
- United States
- HS subheading
- 8540.99
Summary
In the United States tariff, line 8540.99.40.00 covers parts, electron guns; radio frequency (RF) interaction structures for microwave tubes of subheadings 8540.71 through 8540.79, inclusive. Goods under this line enter free of general (MFN) duty. It falls under HS subheading 8540.99 in heading 85.40 (chapter 85).
What this line covers
In the United States tariff, line 8540.99.40.00 covers parts, electron guns; radio frequency (RF) interaction structures for microwave tubes of subheadings 8540.71 through 8540.79, inclusive.
Its legal text is “Electron guns; radio frequency (RF) interaction structures for microwave tubes of subheadings 8540.71 through 8540.79, inclusive”, read under “Parts” and “Other”.
How it is structured
It falls under HS subheading 8540.99 in heading 85.40 (chapter 85). The first six digits are the Harmonized System code; the 4 digits after them are added by the United States tariff.
- 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
- Heading 85.40
- 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
- Subheading 8540.99
- Parts
- Within the subheading
- Other
- Line 8540.99.40.00
- Electron guns; radio frequency (RF) interaction structures for microwave tubes of subheadings 8540.71 through 8540.79, inclusive
Duty
Goods under this line enter free of general (MFN) duty.
Other lines under 8540.99
- 8540.99.80.00Other
In other countries
No other national tariff on border.bot has live lines under 8540.99 yet.
Frequently asked questions
What does tariff line 8540.99.40.00 cover in the United States tariff?
In the United States tariff, line 8540.99.40.00 covers parts, electron guns; radio frequency (RF) interaction structures for microwave tubes of subheadings 8540.71 through 8540.79, inclusive.
What is the general (MFN) duty on 8540.99.40.00 in the United States?
Goods under this line enter free of general (MFN) duty.
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: