What is COE and why do I need to know it?
Coefficient of Thermal Expansion (COE, CoE, CTE, or ECTE) is a number that denotes the rate at which something expands and contracts in a particular temperature range. In glass fusing, when two glasses have the same COE it is said that they are compatible, meaning that they will be likely to fuses together without creating major stresses that will tear them apart. Although COE is a major indicator of compatibility, it is not the only factor; physical and chemical properties of the constituent parts also play a roll in compatibility, as well as the way that the fused whole is treated (see annealing).
