6903.20.00.00
Containing by weight more than 50 percent of alumina (Al2O3) or of a mixture or compound of alumina and of silica (SiO2)
Classification path
- Other refractory ceramic goods (for example, retorts, crucibles, muffles, nozzles, plugs, supports, cupels, tubes, pipes, sheaths, rods and slide gates), other than those of siliceous fossil meals or of similar siliceous earths
- Containing by weight more than 50 percent of alumina (Al2O3) or of a mixture or compound of alumina and of silica (SiO2)
Rates of duty
- General (MFN)
- Free
- Column 2Cuba, North Korea, Russia, Belarus
- 30%
- Unit of quantity
- kg
Related lines in heading 6903
About heading 6903
Other refractory ceramic goods (for example, retorts, crucibles, muffles, nozzles, plugs, supports, cupels, tubes, pipes, sheaths, rods and slide gates), other than those of siliceous fossil meals or of similar siliceous earths
Heading 6903 covers refractory ceramic goods that are not bricks or other constructional shapes, such as crucibles, retorts, muffles, nozzles, tubes, rods and slide gates. The heading is split by composition: goods with more than 50% free carbon, goods with more than 50% alumina or alumina-silica, and all other goods, which separate into clay and non-clay. Every declarable line in this heading carries a general (MFN) duty rate of Free.
Full guide to heading 6903Products in this heading
- Graphite crucibles used for melting metal
- Ceramic kiln furniture such as setters and supports
- Refractory nozzles and slide gates for molten metal flow control
- Alumina tubes and pipes for high-temperature furnaces
- Muffles and retorts for heat treating or firing
- Refractory rods and sheaths for thermocouples and sensors
- Clay-based saggers and cupels used in firing and assaying
Frequently asked questions
What is the HTS code for graphite crucibles with more than 50% carbon?
Refractory ceramic crucibles containing by weight more than 50% of free carbon are classified under 6903.10.00.00, with a general (MFN) duty rate of Free.
What is the duty on alumina refractory tubes?
Refractory tubes containing more than 50% alumina, or more than 50% of an alumina and silica mixture or compound, fall under 6903.20.00.00, with a general (MFN) duty rate of Free.
How do I classify refractory ceramic kiln supports?
If the support meets the free carbon test it goes under 6903.10.00.00 and if it meets the alumina or alumina-silica test it goes under 6903.20.00.00, both at a general (MFN) rate of Free. Otherwise, clay supports are classified under 6903.90.00.10 and other supports under 6903.90.00.50, also Free.
Source: USITC Harmonized Tariff Schedule, retrieved October 21, 2026.