Refractory Kiln Plug
A cordierite ceramic plug used to seal peepholes in pottery kilns, designed to withstand thermal cycling. This fired refractory plug is shaped from clay-silica mixes and fired, meeting Chapter 69 requirements. It is classified under tariff item 6903.90.00, as plugs are explicitly listed in the heading.
Import Duty Rates by Country of Origin
| Origin Country | MFN Tariff | Surtaxes | Total Effective Rate |
|---|---|---|---|
| 🇨🇳China | Free | — | Free |
| 🇲🇽Mexico | Free | — | Free |
| 🇺🇸United States | Free | — | Free |
| 🇩🇪Germany | Free | — | Free |
| 🇯🇵Japan | Free | — | Free |
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If imported as a part of an industrial furnace or kiln
Parts of industrial furnaces are classified in Chapter 84, not as standalone ceramic goods.
If the plug contains more than 50% by weight of alumina
High-alumina refractory plugs fall under this subheading.
Not sure which classification is right?
The Tariff Assistant works through the GRI rules on your specific product to reach the right tariff item — and can price the duty on it in the same conversation.
Import Tips & Compliance
• Confirm the plug is fired above 800°C; lower-temperature products are excluded
• Provide material composition data to support classification
• If the plug is part of a kiln, check if it should be classified with the kiln under Chapter 84
Related Products under Tariff item 6903.90.00
Alumina Ceramic Retort
A high-alumina ceramic retort designed for laboratory pyrolysis and gas synthesis reactions at temperatures exceeding 1600°C. This product is a refractory ceramic good, explicitly named in tariff item 6903.90.00, and is fired after shaping to achieve its high-temperature stability.
Alumina Crucible
A high-purity alumina ceramic crucible used for melting metals or chemicals at high temperatures in laboratories and foundries. This refractory ceramic good is designed to withstand extreme thermal and chemical stress, qualifying under tariff item 6903.90.00.
Ceramic Bushing Support
Recrystallized alumina supports holding heating element bushings in high-temperature electric furnaces. These are fired ceramic goods shaped from alumina and fired above 800°C, qualifying as refractory ceramic supports. Supports are explicitly named in heading 69.03, and the non-clay composition places them under this tariff item.
Ceramic Ladle Plunger
A zirconia-graphite ceramic plunger used for stirring molten steel in secondary refining ladles. This refractory ceramic good is high-fired for extreme corrosion resistance and falls under tariff item 6903.90.00 as an 'other' refractory product.
Ceramic Pug Mill Nozzle
A silicon carbide nozzle for high-pressure ceramic pug mills extruding clay products. This refractory nozzle resists abrasive clay slips and is classified under tariff item 6903.90.00 as an 'other' refractory ceramic good.
Ceramic Retort Tube
Fired mullite ceramic retort tube for gas purification processes at elevated temperatures in industrial chemical applications. This is shaped from mullite and fired above 800°C, making it a fired refractory ceramic good. Retort tubes are explicitly named in heading 69.03, and the non-clay composition places it under this tariff item.