COE

Coefficient of Expansion

When thermal energy is applied to a substance, let's say glass, the energy between the bonds increases and the result is an extension of the bond length. This can result in two types of expansion, linear and volumetric.

Each type of glass that is varied upon its molecular composition will result in a different COE. Although one could create two substances that have identical thermal expansion profiles, glass is typicaly catagorized via it's COE.