Harmonized System
U.S. exports of thermionic and other cathode tubes, not elsewhere specified or included (HS 854089) totaled $8.3M in August 2026.
Importers of Thermionic and Other Cathode Tubes, Not Elsewhere Specified or Included paid $448K in duties in August 2026, an effective tariff rate of 19.34% of the $2.3M imported — duty actually collected as a share of that value, not the published tariff schedule.
Last updated: August 2026 dataGas and vapor electron tubes, diode/triode/tetrode types, light-sensing tubes, and other thermionic or cold-cathode devices that do not fit more specific headings are captured here, spanning applications from photomultiplier tubes in scientific instrumentation to gas-discharge tubes in surge protection. The US schedule subdivides by construction type: gas and vapor tubes (8540890020), diode/triode/tetrode types (8540890040), light-sensing tubes (8540890060), and a residual NESOI line (8540890080). The United Kingdom and Germany lead US import supply, with Russia, China, and Japan also significant—a supplier profile consistent with the heading's mix of legacy European tube manufacturing and Asian volume production.
AI-written summary of the official U.S. Census Bureau trade figures on this page — verify before relying on it.
73 shipments/mo
Photomultiplier tubes, which detect light via photoemission and electron multiplication, are photocathode devices and would typically fall under the light-sensing tubes line (8540890060) within this heading. However, if a specific photomultiplier design is covered by a more specific heading elsewhere in Chapter 85, that heading takes precedence. Importers should review the full chapter structure and consult a licensed customs broker when the application is ambiguous.
Gas and vapor tubes (8540890020) operate by ionizing a gas or vapor fill to conduct current, as in thyratrons or ignitrons, and are used in high-voltage switching and power-control applications. Diode, triode, and tetrode tubes (8540890040) are high-vacuum devices that control electron flow through electrode geometry rather than gas ionization, covering a wide range of amplifier and rectifier applications. The presence or absence of a gas or vapor fill, confirmed by the manufacturer's specification, is the key distinguishing criterion.
HSChapter 85
Trade Directory
List your company under HS 854089 — Thermionic and Other Cathode Tubes, Not Elsewhere Specified or Included, so the companies trading it can find you. Be the first supplier listed.
Subheading 2 of 11 in heading 8540
Subheading 854089 · $8.3M of $42.4M
ImportsExports
Imports
$2.3MYoY · free account
Exports
$8.3MYoY · free account
12-mo low · imports
YoY · free accountOver the twelve months to August 2026, the U.S. imported $32.0M of Thermionic and Other Cathode Tubes, Not Elsewhere Specified or Included.
Through August 2026. Source: U.S. Census Bureau.
HS10 import codes under this HS6 parent, each with its own page. Source: U.S. Harmonized Tariff Schedule.
| Code | Description | Import Value | Effective Tariff % | Dutiable Share | Duty Collected |
|---|---|---|---|---|---|
| 8540890020 | Gas and Vapor Electron Tubes, NESOI | $1.5M | 18.81% | 100.00% | $279K |
| 8540890080 | Thermionic, Cold Cathode or Photocathode Tb, NESOI | $366K | 10.94% | 74.29% | $40K |
| 8540890040 | Diode, Triode, And Tetrode Type Tubes | $356K | 33.12% | 100.00% | $118K |
| 8540890060 | Light-Sensing Tubes | $111K | 10.00% | 100.00% | $11K |
HS10 export codes under this HS6 parent, each with its own page. Source: U.S. Schedule B export classification.
| Code | Description | Export Value |
|---|---|---|
| 8540890020 | Gas and Vapor Electron Tubes, NESOI | $5.3M |
| 8540890040 | Diode, Triode, And Tetrode Type Tubes | $2.1M |
| 8540890080 | Thermionic, Cold Cathode or Photocathode Tb, NESOI | $753K |
| 8540890060 | Light-Sensing Tubes | $56K |
Import lines come from the U.S. Harmonized Tariff Schedule and export lines from Schedule B. The two are numbered by different agencies, so the same 10-digit code can appear in both tables describing a different product.
Exports · August 2026
destination
Singapore and Japan together take 41% of it.
customs district
origin
entry
rate provision · imports
0.6% enters free of duty; duty collected equals 19.34% of total import value.