Preform Collapsing Furnace

High-temperature furnace that heats MCVD-deposited tubes to collapse internal layers into solid optical fiber preforms under controlled atmosphere. Produces symmetrical core-cladding structure. HTS 8475.21.00.00 for this hot working glass machinery.

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.

8417.10.00Higher: 37.9% vs 35%

If standard glass annealing lehrs

Continuous annealing ovens for flat glass products.

7006.00.20Higher: 41.4% vs 35%

If finished collapsed preforms

Actual glass products, not manufacturing equipment.

8475.10.00Same rate: 35%

If lamp tube working equipment

Similar heating for glass envelope assembly.

Not sure which classification is right?

Our AI classifier can analyze your specific product and recommend the correct HTS code with confidence.

Import Tips & Compliance

Specify collapse temperature profiles (2000°C+) unique to silica glass

Avoid general glass annealing oven classification (8417)

Pressure differential system documentation

Related Products under HTS 8475.21.00.00

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Automated hydrofluoric acid etching station removes surface defects from optical fiber preforms, improving fiber strength. Precise chemical dosing and rinsing. HTS 8475.21.00.00 for preform processing machinery.

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Integrated Preform Manufacturing Line

Complete turnkey line combining VAD deposition, sintering, dehydration, and collapsing for high-volume optical fiber preform production. PLC controlled with recipe management. HTS 8475.21.00.00 for complete optical fiber making systems.

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Oven removes hydroxyl impurities from soot preforms using chlorine gas at elevated temperatures, essential for low-loss optical fibers. Controlled humidity environment. Specialized under HTS 8475.21.00.00.

Czochralski Crystal Puller for Optical Fiber Preforms

This machine uses the Czochralski method to grow high-purity silica monocrystalline boules from which optical fiber preforms are sliced. It melts silica in a crucible and slowly pulls a seed crystal to form the boule under precise temperature control. Classified under HTS 8475.21.00.00 as it is specifically designed for producing preforms used in optical fiber manufacturing.