BLENDALLOY 25-5200 is a 52% nickel-iron controlled expansion, glass-to-metal sealing alloy recommended for dry reed switches and mercury wetted relays. 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: Ni-136. Producer or source: Magnetics Inc..