Casted from only the best ASTM-grade 20 iron . Grinded completely around the edge . Every plate leaves no rough edges . Safe for the user and floor . Machined center hole . Coated with a durable Satin Black enamel paint . Baked for one hour to assure a finish that is chip, abrasion and corrosion resistant . Consistent quality casting . High quality Enamel finish . 90-Day limited warranty