Experimentally derived “constants” used to define the behavior of a gasket and/or the assembly and in-service conditions required for acceptable behavior. The term “gasket factor” comes from the Boiler and Pressure Vessel Code, which contains tabulation of m and y factors defining the recommended Gasket stress in-service and at assembly-for design purposes only. (Actual assembly and in-service stresses will usually be greater.) New factors, called Gb, a, and Gs, have recently been proposed for the Code. These factors are not design recommendations, but instead, define the behavior of the gasket.