NILO alloy 36 (UNS K93600 & K93601/W. Nr. 1.3912), a binary nickel-iron alloy containing 36% nickel. Its very low room-temperature thermal expansion coefficient makes it useful for tooling for aerospace composites, standards of length, measuring tapes and gauges, precision components, and pendulum and thermostat rods. It is also used as the low expansion component in bi-metal strip, in cryogenic engineering, and for laser components.