Artificial Corundum

Artificial corundum — fused aluminum oxide produced in electric arc furnaces — is a critical abrasive and refractory material used in grinding wheels, sandpaper, blasting media, and high-temperature furnace linings. The US tariff schedule distinguishes crude artificial corundum (2818101000) from processed grades, including white, pink, and ruby corundum exceeding 97.5% aluminum oxide content (2818102010) and all other forms (2818102090) — distinctions that reflect significant differences in purity, crystal structure, and end-use value. China dominates import supply, making Section 301 tariff exposure a primary cost driver for US buyers, with Austria and Canada as alternative sources.