Sub Headings of 6903
| 6903.10.00.00 | Containing by weight more than50 percent of graphite or other carbon or of a mixture of these products |
| 6903.20.00.00 | Containing by weight more than 50 percent of alumina (Al2O3) or of a mixture or compound of alumina and of silica (SiO2) |
| 6903.90.00. | Other |