Cupel Refractory Dish
Bone ash cupel for precious metal assaying in cupellation furnaces, absorbing base metals. Explicitly named refractory ceramic under HTS 6903.90.00.50.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If porcelain lab ware construction
Lab porcelain/earthenware excludes refractories, goes to 6912
If thinner than 3.2 cm ceramic tile
US tile thickness note affects thin refractory shapes
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Import Tips & Compliance
• Certify bone ash >25% for distinction; lab use declarations; small package exemptions possible
Related Products under HTS 6903.90.00.50
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High-purity alumina ceramic crucible used for melting and holding metals or chemicals at high temperatures in laboratory furnaces. Classified under HTS 6903.90.00.50 as a refractory ceramic good designed for extreme heat resistance, fired after shaping from inorganic nonmetallic materials. Meets chapter requirements for refractory applications beyond basic bricks.
Zirconia Nozzle
Zirconium oxide ceramic nozzle for continuous casting in steel mills, resisting molten metal erosion. Falls under HTS 6903.90.00.50 as other refractory ceramic goods, fired after shaping for high-temperature industrial use. Excludes non-fired or low-temp processed items per chapter notes.
Silicon Carbide Thermocouple Tube
Hexagonal silicon carbide tube sheathing thermocouples in kilns and furnaces up to 1600°C. HTS 6903.90.00.50 covers this refractory ceramic tube, fired from nonmetallic carbides, excluding electrical insulators. Essential for industrial heat measurement protection.
Refractory Ceramic Slide Gate
High-alumina slide gate plates controlling molten steel flow in ladle casting. Classified in HTS 6903.90.00.50 as other refractory ceramic goods (slide gates specifically mentioned), fired after room-temp shaping from oxide materials.
Magnesium Oxide Crucible
MgO ceramic crucible for rare earth metal melting, offering superior corrosion resistance. HTS 6903.90.00.50 applies to this fired refractory oxide vessel, distinct from basic brick forms.
Ceramic Retort Tube
Fired mullite ceramic retort tube for gas purification processes at elevated temperatures. Specifically listed under HTS 6903.90.00.50 as refractory ceramic goods for chemical reactions.