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Insulating Clay Refractory Blocks from China

Lightweight clay refractory blocks with insulating properties for boiler and incinerator construction, fired from shaped clay mixtures. HTS 6902.90.50.10 covers these as clay-based refractory blocks other than siliceous types. They minimize heat loss in high-temperature applications.

Duty Rate — China → United States

37.5%

Rate breakdown

9903.88.0325%Except as provided in headings 9903.88.13, 9903.88.18, 9903.88.33, 9903.88.34, 9903.88.35, 9903.88.36, 9903.88.37, 9903.88.38, 9903.88.40, 9903.88.41, 9903.88.43, 9903.88.45, 9903.88.46, 9903.88.48, 9903.88.56, 9903.88.64, 9903.88.66, 9903.88.67, 9903.88.68, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(e) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(f)
9903.05.3112.5%Section 301 (forced labor) — additional 12.5% ad valorem on products of China

Import Tips

Include thermal conductivity test results (<0.5 W/mK typical) to substantiate refractory insulation claims

Ensure packing lists specify 'fired clay refractory' to avoid scrutiny as unfinished goods

Check for chrome content; if >10%, may require additional hazardous material declarations