Fused Silica Glass Block
Solid block of fused silica glass cast in rectangular form for machining into precision components like telescope mirrors. Classified under HTS 7001.00.10.00 for glass in the mass of fused quartz, retaining mass character post-annealing.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If ground/polished into optical elements
Finished prisms, lenses of quartz classify under 9001 as optical elements.
If made into lead crystal tableware
While fused silica rarely qualifies, lead crystal (24% PbO) goes to 7013.
If spun into glass wool fibers
Fused silica meeting wool specs (SiO2 >=60%) falls under 7019 per chapter note.
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Import Tips & Compliance
• Document annealing only; any grinding/polishing disqualifies from 'in the mass' status
• Specify transmission spectrum (UV to IR); affects end-use declarations for optics vs refractories
• Insure against thermal shock; recommend heated containers for transoceanic shipping
Related Products under HTS 7001.00.10.00
Fused Quartz Glass Ingot
A large, solid mass of high-purity fused quartz glass produced by melting silica at high temperatures, used as raw material for further processing into rods, tubes, or optical components. It falls under HTS 7001.00.10.00 as 'glass in the mass' of fused quartz or other fused silica, prior to any shaping or forming beyond the initial melt.
Synthetic Fused Silica Boule
A cylindrical boule of synthetic fused silica created via flame hydrolysis or electric fusion, serving as stock material for semiconductor and UV optic manufacturing. Classified in HTS 7001.00.10.00 because it is glass in the mass of fused silica, unworked except for annealing.
High-Purity Fused Silica Lump
Irregular lumps of high-purity fused silica obtained directly from the melting furnace, used in refractory linings or remelting. HTS 7001.00.10.00 applies as glass in the mass specifically of fused quartz/silica, excluding waste or cullet.
Electric-Fused Quartz Mass
Bulk mass of quartz glass produced by electric arc fusion, known for low bubble content in high-end applications. It is 'glass in the mass of fused quartz' under HTS 7001.00.10.00, as processes before annealing do not constitute working.
UV-Grade Fused Silica Chunk
Chunks of premium fused silica optimized for ultraviolet transmission, supplied in bulk for optical fabrication. HTS 7001.00.10.00 covers this as unworked glass in the mass of fused silica.
Semiconductor-Grade Fused Quartz Blank
Large blanks of semiconductor-grade fused quartz in mass form for wafer carriers and diffusion tubes. HTS 7001.00.10.00 as it's glass in the mass of fused silica before machining.