invar rod diameter: from 1mm-100mm invar 36 is also known as USN K93600,UNS K93660,alloy 36,ASTM F1684.Nilo 36,etc. invar rod diameter: from 1mm-100mminvar 36 is also known as USN K93600,UNS K93660,alloy 36,ASTM F1684.Nilo 36,etc. Invar 36 is a Nickel-Iron, low expansion alloy containing 36% Nickel, belongs to one of the controlled expansion alloys with the lowest thermal expansion coefficient of ...