Insulating Refractory Castable

Lightweight castable with ceramic fiber and vermiculite for low thermal conductivity furnace backings. Under HTS 3816.00.20 as other refractory concretes, used behind dense linings in heat processing. Balances insulation and strength.

Import Duty Rates by Country of Origin

Origin CountryMFN RateCh.99 SurchargesTotal Effective Rate
🇨🇳China3%+35.0%38%
🇲🇽Mexico3%+10.0%13%
🇨🇦Canada3%+10.0%13%
🇩🇪Germany3%+10.0%13%
🇯🇵Japan3%+10.0%13%

More Specific Codes

This product may fall under a more specific subheading:

Alternative Classifications

This product could be classified differently depending on its characteristics or intended use.

6806.10.00Higher: 38.9% vs 38%

If fiber-dominated without cementitious binders

Mineral wools/fibers alone in 6806; binders create Chapter 38 mix.

6906.00.00.00Lower: 35% vs 38%

If pre-formed insulating firebricks

Shaped products to Chapter 69.

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Import Tips & Compliance

Specify density (<1.5 g/cm³) and K-factor to prove insulating refractory nature

Fiber content requires OSHA MSDS; watch for asbestos misdeclaration