HS code · 6-digit subheading
HS Code 7002.31 – Glass; unworked, in tubes, of fused quartz or other fused silica
HS code 7002.31 is the 6-digit subheading for glass, unworked, in tubes, of fused quartz or other fused silica. It is used for fused quartz furnace tubes, fused silica lamp envelopes (unworked), quartz glass reaction tubes, UV sterilization lamp tubes (unworked) and quartz glass optical waveguides.
What HS 7002.31 covers
This specific HS code covers unworked glass tubes made from fused quartz or other fused silica. These materials are highly prized for their exceptional thermal shock resistance, high-temperature stability, and excellent optical transparency, particularly in the ultraviolet (UV) spectrum. Consequently, these tubes are critical components in high-tech industries such as semiconductor manufacturing, advanced laboratory equipment, UV sterilization systems, and specialized lighting applications. Importers and exporters are typically specialized glass manufacturers, high-tech component suppliers, and scientific instrument producers. The trade in these tubes is driven by the demand for materials that can withstand extreme conditions and provide superior optical performance, making them essential for precision and high-performance applications.
- Covers
- Fused quartz furnace tubes
- Fused silica lamp envelopes (unworked)
- Quartz glass reaction tubes
- UV sterilization lamp tubes (unworked)
- Quartz glass optical waveguides
- Fused silica capillary tubes
- Quartz glass process tubes
- Examples
- Heraeus Quartz
- Shin-Etsu Quartz
- Momentive Technologies
- QSIL
Codes often confused with 7002.31
Common mistake. Often confused with 700239 (other unworked glass tubes) if the specific material (fused quartz/silica) is not clearly identified, or 7011 (glass envelopes for electric lamps) if already processed into a finished lamp component.
Top exporters and importers of HS code 700231, 2025
In 2025, the largest exporter of HS code 700231 in UN Comtrade data was the United States, with 43% of world exports; the largest importer in UN Comtrade data was the United States, with 19% 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 United States $155M 43% of world exports
- 2 Germany $100M 28% of world exports
- 3 China $40M 11% of world exports
World total: $363M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 United States $97M 19% of world imports
- 2 Mexico $83M 17% of world imports
- 3 China $62M 12% of world imports
World total: $504M 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 7002.31
Brazil does not split HS 7002.31: its NCM code is 7002.31.00.
All Brazil NCM codes in heading 70.02 →
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.
Questions about HS 7002.31
What is HS code 700231?
HS code 700231 is a 6-digit subheading in the Harmonized System that covers: Glass; unworked, in tubes, of fused quartz or other fused silica. This specific HS code covers unworked glass tubes made from fused quartz or other fused silica. These materials are highly prized for their exceptional thermal shock resistance, high-temperature stability, and excellent optical transparency, particularly in the ultraviolet (UV) spectrum. Consequently, these tubes are critical components in high-tech industries such as semiconductor manufacturing, advanced laboratory equipment, UV sterilization systems, and specialized lighting applications. Importers and exporters are typically specialized glass manufacturers, high-tech component suppliers, and scientific instrument producers. The trade in these tubes is driven by the demand for materials that can withstand extreme conditions and provide superior optical performance, making them essential for precision and high-performance applications.
What products fall under HS code 700231?
Fused quartz furnace tubes, fused silica lamp envelopes (unworked), quartz glass reaction tubes, UV sterilization lamp tubes (unworked), quartz glass optical waveguides, fused silica capillary tubes, quartz glass process tubes
What are common misclassifications for HS code 700231?
Often confused with 700239 (other unworked glass tubes) if the specific material (fused quartz/silica) is not clearly identified, or 7011 (glass envelopes for electric lamps) if already processed into a finished lamp component.
Which countries are the top exporters of goods under HS code 700231?
In 2025, the top exporters of HS code 700231 in UN Comtrade data were the United States ($155M, 43% of world exports), Germany ($100M) and China ($40M). World exports came to about $363M, 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 700231?
In 2025, the top importers of HS code 700231 in UN Comtrade data were the United States ($97M, 19% of world imports), Mexico ($83M) and China ($62M). World imports came to about $504M, 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 700231 structured?
HS code 700231 is a 6-digit subheading under the Harmonized System. The first 2 digits (70) identify the chapter, digits 3-4 (02) identify the heading, and digits 5-6 (31) specify the subheading. This code is standardized globally by the World Customs Organization.
What is the Brazil NCM code for HS code 700231?
In Brazil, HS code 700231 is NCM 7002.31.00. The last two digits are 00 because Brazil does not split this HS code further.