Refractory Nonconstructional Ceramic Goods — Other (Retorts, Muffles, Nozzles, Plugs, etc.)

Silicon carbide kiln furniture (setters, saggers, beams, and posts) generally classifies under 6903.90 as nonclay refractory nonconstructional ceramic goods (6903900050), provided the article is not predominantly carbon by weight (which would place it in 6903.10) and is not a constructional shape. The nonclay line captures SiC and other non-alumina/silica-dominant compositions used as process support equipment in ceramics and electronics firing.

Customs may request a material composition certificate or laboratory analysis confirming whether the refractory article is clay-based (phyllosilicate minerals such as kaolinite, ball clay, or fireclay) or nonclay (SiC, magnesia, zirconia, etc.). Supplier-issued material data sheets specifying mineralogical composition and firing temperature are the standard supporting documents. Retaining these records is advisable given that the clay/nonclay split affects both classification and, potentially, applicable trade-remedy exposure.