Monel 400 is a single phase, solid-solution nickel-copper alloy that offers superior resistance to many corrosive environments over temperatures ranging from sub-zero to 800°F. This alloy is only hardenable through cold working, rather than heat treatment. The Curie Temperature of this alloy lies in the ambient temperature range and is affected by variations in the alloy's chemical composition. Caution is advised in applications where strong nonmagnetic characteristics are desired. The ratio of copper to nickel in Monel 400 is almost identical to that found in the ore the metal is derived from. This alloy was first patented over 100 years ago, and it continues to be one of the most commonly used corrosion resistant alloys commercially produced.