MACOR

Macor is the trademark for a machineable glass-ceramic developed and sold by Corning Inc. It is a white material that looks somewhat like porcelain. Macor has particular thermal characteristics, acting as efficient insulation, and stable up to temperatures of 1000 °C, with very little thermal expansion or outgassing. It can be machined into any shape using standard metalworking bits and tools. This combination of machineability and good thermal properties have made it the material of choice in many engineering contexts.

Read more about MACOR:  Composition, Properties, Safety, Applications