text: There are many factors to consider when choosing the best base metal for your gasket application. Is the gasket material compatible with the contact surfaces? Are there temperature limits? What are the bolt specs? What is the flange clamping pressure? What is the seating stress required to provide a proper seal? Copper is a popular choice for many, as it exhibits many favorable properties for a range of applications. They are commonly used in applications exposed to coke oven gas, refined gasoline, kerosene and beer, among others. Copper is strong, yet malleable enough to nest into contact faces when tightening the fastening bolts, providing for an excellent seal. The elasticity properties are such that a 10-inch piece of copper may be stretched up to 12.5 inches before the material ruptures. It is that combination of strength and forming ability that makes copper a very popular choice.