HS code · 6-digit subheading
HS Code 8540.79 – Tubes; microwave (for example klystrons, travelling wave tubes, carlinotrons), excluding magnetrons and grid-controlled tubes
HS code 8540.79 is the 6-digit subheading for tubes, microwave (for example klystrons, travelling wave tubes, carlinotrons), excluding magnetrons and grid-controlled tubes. It is used for klystrons, travelling wave tubes (TWTs), backward wave oscillators (BWOs), gyrotrons and inductive output tubes (IOTs).
What HS 8540.79 covers
This category covers a range of specialized microwave tubes, such as klystrons, travelling wave tubes (TWTs), and carlinotrons, excluding magnetrons and grid-controlled tubes. These devices are essential for generating, amplifying, or modifying high-frequency electromagnetic waves, finding critical applications in satellite communications, radar systems, particle accelerators, and high-power scientific research. The international trade involves high-value, low-volume components. Importers are typically telecommunications companies, aerospace and defense contractors, research institutions, and manufacturers of advanced scientific instruments. Exporters are countries with highly sophisticated electronics and vacuum tube manufacturing capabilities. Key aspects of this trade include extreme precision, high reliability, specific frequency and power requirements, and often export controls due to their strategic importance. The market is highly specialized and driven by technological advancements in communication and defense.
- Covers
- Klystrons
- Travelling wave tubes (TWTs)
- Backward wave oscillators (BWOs)
- Gyrotrons
- Inductive output tubes (IOTs)
- Extended interaction klystrons
- Helix TWTs
- Coupled-cavity TWTs
- Examples
- L3Harris TWT (satellite communication)
- CPI Klystron (particle accelerator)
- Thales TWT (radar system)
- Varian Klystron (medical linear accelerator)
- Teledyne TWT (electronic warfare)
Codes often confused with 8540.79
Common mistake. This code is distinct from 854071 (magnetrons) and 854081 (receiver/amplifier valves), as it covers other specific types of microwave tubes. It should also not be confused with complete satellite communication equipment (851762) or radar apparatus (852610).
Top exporters and importers of HS code 854079, 2025
In 2025, the largest exporter of HS code 854079 in UN Comtrade data was France, with 28% of world exports; the largest importer in UN Comtrade data was the United States, with 23% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.
Top exporters 2025 · share of world exports
- 1 France $98M 28% of world exports
- 2 United States $88M 25% of world exports
- 3 Germany $72M 20% of world exports
World total: $354M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 United States $66M 23% of world imports
- 2 Japan $44M 15% of world imports
- 3 Canada $27M 9.5% of world imports
World total: $286M Reported figures on UN Comtrade ↗
How these figures are built
109 countries reported 2025 trade to UN Comtrade in HS 2022, and their own totals are used. Countries that did not report are estimated from what other countries recorded trading with them. Those estimates miss trade with other non-reporting countries, so they can be low, and a non-reporting country can rank higher than shown or be missing from the list. World totals add both and leave out trade between two non-reporting countries. Figures are in current US dollars; reported imports are mostly valued CIF and exports FOB, and exports include re-exports. The UN Comtrade links show the underlying records; they can also list a few reporters left out here (regional groups and older HS editions).
Source: UN Comtrade (United Nations Statistics Division), 2025 annual data.
Brazil NCM code for 8540.79
Brazil does not split HS 8540.79: its NCM code is 8540.79.00.
All Brazil NCM codes in heading 85.40 →
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.
Questions about HS 8540.79
What is HS code 854079?
HS code 854079 is a 6-digit subheading in the Harmonized System that covers: Tubes; microwave (for example klystrons, travelling wave tubes, carlinotrons), excluding magnetrons and grid-controlled tubes. This category covers a range of specialized microwave tubes, such as klystrons, travelling wave tubes (TWTs), and carlinotrons, excluding magnetrons and grid-controlled tubes. These devices are essential for generating, amplifying, or modifying high-frequency electromagnetic waves, finding critical applications in satellite communications, radar systems, particle accelerators, and high-power scientific research. The international trade involves high-value, low-volume components. Importers are typically telecommunications companies, aerospace and defense contractors, research institutions, and manufacturers of advanced scientific instruments. Exporters are countries with highly sophisticated electronics and vacuum tube manufacturing capabilities. Key aspects of this trade include extreme precision, high reliability, specific frequency and power requirements, and often export controls due to their strategic importance. The market is highly specialized and driven by technological advancements in communication and defense.
What products fall under HS code 854079?
Klystrons, Travelling wave tubes (TWTs), Backward wave oscillators (BWOs), Gyrotrons, Inductive output tubes (IOTs), Extended interaction klystrons, Helix TWTs, Coupled-cavity TWTs
What are common misclassifications for HS code 854079?
This code is distinct from 854071 (magnetrons) and 854081 (receiver/amplifier valves), as it covers other specific types of microwave tubes. It should also not be confused with complete satellite communication equipment (851762) or radar apparatus (852610).
Which countries are the top exporters of goods under HS code 854079?
In 2025, the top exporters of HS code 854079 in UN Comtrade data were France ($98M, 28% of world exports), the United States ($88M) and Germany ($72M). World exports came to about $354M, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
Which countries are the top importers of goods under HS code 854079?
In 2025, the top importers of HS code 854079 in UN Comtrade data were the United States ($66M, 23% of world imports), Japan ($44M) and Canada ($27M). World imports came to about $286M, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
How is HS code 854079 structured?
HS code 854079 is a 6-digit subheading under the Harmonized System. The first 2 digits (85) identify the chapter, digits 3-4 (40) identify the heading, and digits 5-6 (79) specify the subheading. This code is standardized globally by the World Customs Organization.
What is the Brazil NCM code for HS code 854079?
In Brazil, HS code 854079 is NCM 8540.79.00. The last two digits are 00 because Brazil does not split this HS code further.