Section 15 BASE METALS AND ARTICLES OF BASE METAL 81 Other base metals; cermets; articles thereof 81 05 Cobalt mattes and other intermediate products of cobalt metallurgy; cobalt and a 81 05 20 81 05 20 00 Commodity Code Description 81 05 20 00 00 - Cobalt mattes and other intermediate products of cobalt metallurgy; unwrought cobalt;