Product classification

HS code for Refractory ceramic products: 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.

Classification of refractory ceramic products under HS 6903.90

HS code 6903.90 is a residual category for refractory ceramic goods such as retorts, crucibles, muffles, nozzles, and plugs that do not meet the specific material requirements of subheadings 6903.10 (graphite/carbon) or 6903.20 (alumina/silica). These items are used primarily in metallurgical, chemical, and glass-making industries for handling molten materials. The classification is based on the refractory nature of the ceramic (resistance to high heat) and the specific shape or function of the article, provided it is not a brick, block, or tile. This category includes advanced ceramic compositions like silicon carbide, zirconia, or specialized nitrides. These products are often precision-engineered to withstand extreme thermal shock and chemical erosion from molten metals or acids. Because they are finished articles rather than construction materials, they are distinct from the bricks found in heading 6902.

Covers
  • Silicon carbide crucibles
  • Zirconia nozzles for continuous casting
  • Ceramic immersion tubes
  • Refractory muffles for heat treatment
  • Ceramic kiln furniture (setters and saggers)
Also under 6903.90
  • 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 code is often confused with HS code 6902.90, which covers refractory bricks and tiles. The distinction is that 6903 is for laboratory or industrial "ware" (vessels, tubes, etc.) rather than structural "construction" goods. It is also sometimes confused with 6806, which covers mineral wools and expanded mineral materials used for insulation, which are not ceramic-bonded refractory articles.

6902.90Refractory bricks, blocks, tiles and similar refractory ceramic constructional goods; n.e.c. in item no. 6902.1 or 6902.269.03Ceramic goods; (e.g. retorts, crucibles, muffles, nozzles, plugs, supports cupels, tubes, pipes, sheaths, rods and slide gates) excluding those of siliceous fossil meals or of similar siliceous earths68.06Slag, rock wool and similar mineral wools; exfoliated vermiculite, expanded clays, foamed slag, mixtures and articles of heat, sound insulating or sound-absorbing mineral materials

Top exporters and importers of HS 690390 (the code used for refractory ceramic products), 2025

In 2025, the largest exporter of HS 690390 (the code used for refractory ceramic products) 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.

Figures cover everything classified under HS 690390, not only refractory ceramic products.

Top exporters 2025 · share of world exports

  1. 1 United States $193M
  2. 2 China $159M
  3. 3 Germany $158M

World total: $958M Reported figures on UN Comtrade ↗

Top importers 2025 · share of world imports

  1. 1 United States $175M
  2. 2 China $132M
  3. 3 South Korea $84M

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 refractory ceramic products

Brazil splits HS 6903.90 into 6 NCM codes. Pick the one that matches your product:

Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.

Questions about refractory ceramic products

What is the HS code for Refractory ceramic products?

The HS code for Refractory ceramic products is 690390 (Refractory ceramic goods; composition of which n.e.c. in heading no. 6903, other than those of siliceous fossil meals or similar earths). The HS code for other refractory ceramic goods (like crucibles or nozzles) not containing graphite or high alumina/silica is 6903.90.

How do I classify Refractory ceramic products for customs?

Refractory ceramic products is classified under HS code 690390 — 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 a 6-digit subheading level code.

Are ceramic crucibles classified here?

Yes, if they are refractory and do not contain more than 50% graphite or alumina/silica, they fall under 6903.90.

Which countries are the top exporters of refractory ceramic products (HS 690390)?

In 2025, the top exporters of HS 690390 (the code used for refractory ceramic products) 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 refractory ceramic products (HS 690390)?

In 2025, the top importers of HS 690390 (the code used for refractory ceramic products) 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.

Is the HS code for Refractory ceramic products the same in all countries?

The base HS code 690390 for Refractory ceramic products is internationally standardized for the first 6 digits across 200+ countries. Individual countries may add additional digits for national tariff lines and specific classifications.

What is the NCM code for refractory ceramic products in Brazil?

Brazil splits HS 690390 into 6 NCM codes, so the right one for refractory ceramic products depends on the product's details: 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).