... 4.High hardness 5.Entire specification High Purity Alumina Ceramic Tube are widely used in thermocouple protections and some are ... We mainly produce alumina tubes, rods and various industrial ceramic parts, which are mainly used in thermalcouple temperature, liquid ... , instrumentation, mechanical workout, military project etc industry. Furnace tube OD25~3031~4041~5051~6061~7071~8081~9091~100ID19~2324 ...