32590 - Structural clay products (Miscellaneous)
32591 - Vitrified clay sewer pipe & Fittings
32592 - Structural clay products (General) Terra cotta, Drain tile, Flue tile, Roofing tile, Conduit, Chimney, etc.
3259XX0 - - Structural clay products (Miscellaneous - Volume)
3259XX2 - - Structural clay products (Miscellaneous - Speciality)