Section 06 PRODUCTS OF THE CHEMICAL OR ALLIED INDUSTRIES 28 INORGANIC CHEMICALS; ORGANIC OR INORGANIC COMPOUNDS OF PRECIOUS METAL, OFRARE-EARTH METALS, OF RADIOACTIVE ELEMENTS OR OF ISOTOPES 28 49 CARBIDES, WHETHER OR NOT CHEMICALLY DEFINED. 28 49 20 CARBIDES OF SILICON Commodity Code Description 28 49 20 00 CARBIDES OF SILICON