A Nickel-Iron, low expansion alloy containing 36% Nickel. It maintains nearly constant dimensions over the range of normal atmospheric temperatures and has a low coefficient of expansion from cryogenic temperatures to about +500°C. Nilo 36 also retains good strength and toughness at cryogenic temperatures. Applications include standards of length, thermostat rods, laser components and tanks and piping for the storage and transportation of liquefied gasses.