CARPENTER 42 C015
A low expansion metal used as an end fittings to hold the carbon face in a high temperature metal bellows seal.
The main use for this metal is to prevent the metal expansion from loosening the carbon seal face.
Carpenter 42 has a thermal expansion rate almost the same as carbon. Invar 36 is another metal used for this application.
Neither of these metals offers much in the way of corrosion resistance, so the application is limited to non-corrosive fluids.
High temperature oils, monomer and polymer sealing have been the main applications to date.