Fused Silica Investment Casting Shell Tubes

Unworked fused quartz tubes used as drain/vent lines in ceramic shell investment casting molds for aerospace turbine blades. High-temperature stability prevents shell cracking. Classified 7002.31.00.00 as unworked fused silica tubes.

Import Duty Rates by Country of Origin

Origin CountryMFN RateCh.99 SurchargesTotal Effective Rate
🇨🇳ChinaFree+35.0%35%
🇲🇽MexicoFree+10.0%10%
🇨🇦CanadaFree+10.0%10%
🇩🇪GermanyFree+10.0%10%
🇯🇵JapanFree+10.0%10%

Alternative Classifications

This product could be classified differently depending on its characteristics or intended use.

6902.10Lower: 10% vs 35%

If refractory grade fused silica tubes

Investment casting furnace tubes classify as refractory goods.

6815.99Lower: 10% vs 35%

If articles of fused silica fibers

Fiber-reinforced casting tubes become composite articles.

7007.29.00.00Higher: 39.9% vs 35%

If drawn into multiple capillary arrays

Multi-bore fused silica tubes for casting become profiled tubes.

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Import Tips & Compliance

Thermal expansion coefficient data matches investment casting requirements

Multiple thin-wall diameters bundled shipment common—invoice separately

Related Products under HTS 7002.31.00.00

Fused Quartz Semiconductor Processing Tubes

Long, unworked tubes of fused quartz used in semiconductor diffusion furnaces and CVD reactors. Their extreme purity prevents contamination during wafer processing at high temperatures. Falls under 7002.31.00.00 for unworked fused silica tubes.

Fused Quartz Optical Fiber Drawing Tubes

Precision unworked tubes of fused silica used in optical fiber preform collapse and drawing towers. Their clarity and low impurity levels are critical for single-mode fiber production. HTS 7002.31.00.00 applies to these unworked fused quartz tubes.

Fused Quartz Solar Simulator Tubes

Unworked fused silica tubes serving as test chambers for photovoltaic cell evaluation under concentrated solar simulation. High solar transmission (down to 200nm) maintained through purity. HTS 7002.31.00.00 for unworked tubes of fused quartz.

Synthetic Fused Quartz Process Gas Tubes

Unworked synthetic fused silica tubes for delivering process gases in semiconductor and solar cell manufacturing. Flame-polished ends acceptable if pre-annealing per chapter notes. HTS 7002.31.00.00 covers these unworked tubes.

Fused Quartz Tubing for Laboratory Reactors

Unworked tubes made from fused quartz or fused silica, supplied in straight lengths without further processing beyond forming and annealing. These tubes are essential components in laboratory equipment like reactors and distillation apparatus due to their high thermal resistance and chemical inertness. Classified under HTS 7002.31.00.00 as unworked tubes of fused quartz or other fused silica.

Fused Silica Capillary Tubes

Thin-walled, unworked capillary tubes of fused silica used primarily in gas chromatography and analytical instruments. These tubes maintain optical clarity and purity essential for precise measurements. HTS 7002.31.00.00 covers them as unworked tubes of fused quartz or other fused silica.