COE (Coefficient of Expansion)

A mathematical formula expressing a glass type’s response to temperature change. Lampworkers tend to use a shorthanded number rather than a whole formula to refer to each glass type. For instance, 104 COE refers to glass in the Effetre line, as well as many other glass lines. Some popular glass lines and their (most commonly seen) COEs are:

Borosilicate – 33 COE
Bullseye – 90 COE
Uroboros – 96 COE
Spectrum – 96 COE
Lauscha – 104 COE
CiM – 96-104COE
Effetre – 104 COE
Vetrofond – 104 COE
Satake – 125 COE