The 42 Nickel-Iron alloy has the lowest expansivity of the Iron-Nickel alloys that are commonly used for glass-sealing applications. Its thermal expansion closely matches the 1075 glass and it is sometimes used for sealing action with the 0120 and 0010 glasses. It is made close metallurgical control to provide uniformity of performance. Its many uses include industrial lamps, ceramic-to-glass seals, and sealed-beam automobile headlamps. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Fe-66. Producer or source: Iron-nickel alloy mills.