HS code · 6-digit subheading
HS Code 6903.90 – Refractory ceramic goods; composition of which n.e.c. in heading no. 6903, other than those of siliceous fossil meals or similar earths
HS code 6903.90 is the 6-digit subheading for refractory ceramic goods, composition of which n.e.c. in heading no. 6903, other than those of siliceous fossil meals or similar earths. It is used for zirconia crucibles, silicon carbide kiln furniture, chromia-based nozzles, boron nitride components and fused cast zirconia shapes.
What HS 6903.90 covers
This is the residual HS code for all other refractory ceramic goods, not being bricks, blocks, or tiles, that do not fit the specific compositional criteria of 690310 (free carbon) or 690320 (alumina/silica). This broad category encompasses a wide array of highly specialized refractory shapes, components, and articles made from various advanced ceramic materials like zirconia, silicon carbide, chromia, or complex composites. These items are used in extremely demanding, niche industrial applications where specific properties beyond standard refractories are required, such as in aerospace, chemical processing, or specialized metallurgical operations. Importers are highly specialized industries seeking bespoke high-performance ceramic solutions. Exporters are advanced ceramic manufacturers with expertise in producing these complex and often custom-engineered materials. Their trade reflects the cutting-edge of materials science and industrial innovation.
- Covers
- Zirconia crucibles
- Silicon carbide kiln furniture
- Chromia-based nozzles
- Boron nitride components
- Fused cast zirconia shapes
- Reaction-bonded silicon carbide parts
- Ceramic foam filters
- Examples
- Saint-Gobain ZirPro zirconia components
- Morgan Advanced Materials silicon carbide products
- CoorsTek advanced ceramic shapes
- Vesuvius ceramic filters
Codes often confused with 6903.90
Common mistake. This is the catch-all for non-constructional refractory ceramic goods not covered by 690310 or 690320. It can be confused with 690290 if the item is a brick/block, or with 681599 if the article is mineral-based but not truly ceramic.
Top exporters and importers of HS code 690390, 2025
In 2025, the largest exporter of HS code 690390 in UN Comtrade data was the United States, with 20% of world exports; the largest importer in UN Comtrade data was the United States, with 15% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.
Top exporters 2025 · share of world exports
- 1 United States $193M 20% of world exports
- 2 China $159M 17% of world exports
- 3 Germany $158M 16% of world exports
World total: $958M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 United States $175M 15% of world imports
- 2 China $132M 11% of world imports
- 3 South Korea $84M 7.2% of world imports
World total: $1.2B Reported figures on UN Comtrade ↗
How these figures are built
109 countries reported 2025 trade to UN Comtrade in HS 2022, and their own totals are used. Countries that did not report are estimated from what other countries recorded trading with them. Those estimates miss trade with other non-reporting countries, so they can be low, and a non-reporting country can rank higher than shown or be missing from the list. World totals add both and leave out trade between two non-reporting countries. Figures are in current US dollars; reported imports are mostly valued CIF and exports FOB, and exports include re-exports. The UN Comtrade links show the underlying records; they can also list a few reporters left out here (regional groups and older HS editions).
Source: UN Comtrade (United Nations Statistics Division), 2025 annual data.
Brazil NCM codes for 6903.90 6
Brazil splits HS 6903.90 into 6 NCM codes, Mercosur's 8-digit tariff lines.
- 6903.90.1 TubesTubos Group
- 6903.90.11 Silicon carbide refractory tubesDe carboneto de silício
- 6903.90.12 Zirconium compound refractory tubesDe compostos de zircônio
- 6903.90.19 Other refractory ceramic tubesOutros
- 6903.90.9 OtherOutros Group
- 6903.90.91 Other silicon carbide refractory goodsDe carboneto de silício
- 6903.90.92 Other zirconium compound refractory goodsDe compostos de zircônio
- 6903.90.99 Other refractory ceramic goodsOutros
All Brazil NCM codes in heading 69.03 →
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.
Questions about HS 6903.90
What is HS code 690390?
HS code 690390 is a 6-digit subheading in the Harmonized System that covers: Refractory ceramic goods; composition of which n.e.c. in heading no. 6903, other than those of siliceous fossil meals or similar earths. This is the residual HS code for all other refractory ceramic goods, not being bricks, blocks, or tiles, that do not fit the specific compositional criteria of 690310 (free carbon) or 690320 (alumina/silica). This broad category encompasses a wide array of highly specialized refractory shapes, components, and articles made from various advanced ceramic materials like zirconia, silicon carbide, chromia, or complex composites. These items are used in extremely demanding, niche industrial applications where specific properties beyond standard refractories are required, such as in aerospace, chemical processing, or specialized metallurgical operations. Importers are highly specialized industries seeking bespoke high-performance ceramic solutions. Exporters are advanced ceramic manufacturers with expertise in producing these complex and often custom-engineered materials. Their trade reflects the cutting-edge of materials science and industrial innovation.
What products fall under HS code 690390?
Zirconia crucibles, Silicon carbide kiln furniture, Chromia-based nozzles, Boron nitride components, Fused cast zirconia shapes, Reaction-bonded silicon carbide parts, Ceramic foam filters
What are common misclassifications for HS code 690390?
This is the catch-all for non-constructional refractory ceramic goods not covered by 690310 or 690320. It can be confused with 690290 if the item is a brick/block, or with 681599 if the article is mineral-based but not truly ceramic.
Which countries are the top exporters of goods under HS code 690390?
In 2025, the top exporters of HS code 690390 in UN Comtrade data were the United States ($193M, 20% of world exports), China ($159M) and Germany ($158M). World exports came to about $958M, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
Which countries are the top importers of goods under HS code 690390?
In 2025, the top importers of HS code 690390 in UN Comtrade data were the United States ($175M, 15% of world imports), China ($132M) and South Korea ($84M). World imports came to about $1.2B, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
How is HS code 690390 structured?
HS code 690390 is a 6-digit subheading under the Harmonized System. The first 2 digits (69) identify the chapter, digits 3-4 (03) identify the heading, and digits 5-6 (90) specify the subheading. This code is standardized globally by the World Customs Organization.
What is the Brazil NCM code for HS code 690390?
Brazil splits HS code 690390 into 6 NCM codes: 6903.90.11 (Silicon carbide refractory tubes), 6903.90.12 (Zirconium compound refractory tubes), 6903.90.19 (Other refractory ceramic tubes), 6903.90.91 (Other silicon carbide refractory goods), 6903.90.92 (Other zirconium compound refractory goods), 6903.90.99 (Other refractory ceramic goods). The first 6 digits of each match the HS code.