U.S. imports of Unworked Glass Tubes — Low Thermal Expansion (≤5×10⁻⁶/K) (HS 700232) totaled $1.7M in August 2026, imported from 10 countries.
Importers of Unworked Glass Tubes — Low Thermal Expansion (≤5×10⁻⁶/K) paid $167K in duties in August 2026, an average duty rate of 10.06% — duty actually collected as a share of the imports that cleared customs, not the published tariff schedule. Unworked Glass Tubes — Low Thermal Expansion (≤5×10⁻⁶/K) imports of $1.7M in August 2026 ran 12% above the year-to-date monthly average of $1.5M.
Last updated: August 2026 dataBorosilicate and other technically defined low-expansion glass tubes — those with a linear coefficient of expansion not exceeding 5×10⁻⁶ per Kelvin across 0–300°C — occupy this heading, covering the workhorse material of laboratory glassware, pharmaceutical packaging, and industrial process equipment. Germany and Czech Republic are the leading suppliers, a reflection of Europe's deep borosilicate manufacturing heritage. The single US tariff line, 7002320000, means the thermal-expansion specification is the critical classification boundary separating this heading from both fused-silica tubes (700231) and general glass tubes (700239).
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81 import shipments a month
The thermal expansion coefficient is typically established by the manufacturer's technical data sheet or a third-party materials test report. CBP may request this documentation to confirm classification under 7002320000 versus the residual glass tube heading. Importers should retain test certificates in their entry records, as post-entry audits in the glass sector sometimes focus on this specification boundary.
Both countries host long-established borosilicate glass producers with vertically integrated operations — from raw batch formulation through precision tube drawing — that supply pharmaceutical, laboratory, and industrial customers globally. Their technical consistency and regulatory compliance documentation (important for pharmaceutical-grade tubing) make them preferred sources for US buyers requiring tight dimensional and chemical tolerances.
Subheading 3 of 5 in heading 7002
Subheading 700232 · $1.7M of $21.0M
ImportsExports
Imports
$1.7MYoY · free account
Exports
$540KYoY · free account
12-mo low · imports
Low · free accountOver the twelve months to August 2026, the U.S. imported $16.7M of Unworked Glass Tubes — Low Thermal Expansion (≤5×10⁻⁶/K) and exported $10.9M.
Through August 2026. Source: U.S. Census Bureau.
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Imports · August 2026
origin
Germany and Czech Republic together supply 97% of it.
customs district
destination
entry
rate provision · imports
0.3% enters free of duty; duty collected equals 10.06% of imports for consumption.
HS10 import codes under this HS6 parent, each with its own page. Source: U.S. Harmonized Tariff Schedule.
| Code | Description | Imports for consumption | Average duty rate | Dutiable Share | Duty Collected |
|---|---|---|---|---|---|
| 7002320000 | Tubes of Oth Glass Nes W Lin Coef Ov 5x10-6/Kelvin | $1.7M | 10.06% | 99.75% | $167K |
HS10 export codes under this HS6 parent, each with its own page. Source: U.S. Schedule B export classification.
| Code | Description | Export Value |
|---|---|---|
| 7002320000 | Tubes of Oth Glass Nes W Lin Coef Ov 5x10-6/Kelvin | $540K |
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.