Abstract: An iron-nickel base alloy containing 0.10% Max. carbon, 2% Max. manganese, 1% Max. silicon, 13.5-16% chromium, 24-28% nickel, 1-1.75% molybdenum, 1.6-2.7% titanium, 0.7-1.2% columbium, 0.5% Max. vanadium, 0.35% Max. aluminum, 0.001-0.01% boron, and the balance iron plus incidental impurities having improved strength as compared to A-286 Alloy and capable of attaining at least about 180 ksi yield strength when cold worked as little as about 15% and precipitation hardened. The alloy is especially useful in making large massive parts such as retaining rings which are substantially fully austenitic and nonmagnetic for the rotor windings of very large electric generators.