This industry comprises establishments primarily engaged in shaping, molding, baking, burning, or hardening clay refractories, nonclay refractories, ceramic tile, structural clay tile, brick, and other structural clay building materials. Manufacturing glass blocks--are classified in Industry 32721, Glass and Glass Product Manufacturing; Manufacturing concrete brick and block--are classified in Industry 32733, Concrete Pipe, Brick, and Block Manufacturing; and Manufacturing resilient flooring--are classified in Industry 32619, Other Plastics Product Manufacturing.