| Silicon Oxide | Aluminum Oxide | Magnesium Oxide |
| Titanium Oxide | Zirconium Oxide |
| 3M | Advanced Ceramics Limited | Aremco |
| ATI Wah Chang | CeramTec North America | Channel Industries |
| Corning Incorporated | Esstech | Malvern Minerals Company |
| Mateck GmbH | Microtherm Group | Thermoseal Inc. |