... professional factory We are selling Kovar sheet,Invar sheet,alloy 52 sheet,etc.Controlled Expansion AlloyFor applications where metals ... supplies:InvarInvar is a low expansion alloy, consisting of 36% Nickel, balance Iron. This alloy exhibits extremely low expansion around ambient temperatures ... , lead frames, especially for glass and ceramic seals. Alloy 42 is also known as Pernifer 42, NILO 42, ...