HS Code for Silica refractories

Silica refractories, excluding bricks and structural shapes, are classified under HS code 6903.20. This classification is part of Chapter 69 (Ceramic products) and heading 6903, which covers "Other refractory ceramic goods." This heading is distinct from 6902 because it includes functional industrial items such as retorts, crucibles, muffles, nozzles, plugs, and supports, rather than constructional goods like bricks. Subheading 6903.20 specifically applies to these items when they contain more than 50% by weight of alumina or a mixture of alumina and silica. These products are vital in metallurgical, chemical, and glass-making processes where materials must remain inert and stable at extreme temperatures. The classification is determined by the chemical composition (silica/alumina content) and the fact that the items are fired ceramic refractory components.

Products Included

• Silica-alumina crucibles
• Refractory ceramic muffles
• Silica-based casting nozzles
• Refractory tubing and rods
• Ceramic kiln furniture containing >50% silica/alumina
• Foundry ladles and stoppers

Common Misclassification

These items are often confused with HS code 6902.20. The distinction lies in the application: 6902 is for constructional goods (bricks, tiles), while 6903 is for laboratory or industrial equipment (cruicibles, tubes). Another misclassification involves HS code 7017.10, which covers laboratory glassware made of fused silica. If the item is a fired ceramic (opaque, crystalline structure), it belongs in 6903; if it is fused silica glass (transparent or translucent, non-crystalline), it belongs in 7017. Finally, items made of carbon-bonded silica might be misclassified under 6903.10 if the graphite content is predominant.

FAQ

What is the HS code for silica refractories?

Functional silica-based refractory goods like crucibles and nozzles are classified under HS code 6903.20.

How do I distinguish between ceramic refractories and silica glassware?

Ceramic refractories (6903) are typically opaque and fired from clay or mineral mixes, while silica glassware (7017) is made from melted (fused) quartz and is usually transparent or translucent.