This specification covers the property requirements and corresponding test methods for two iron-nickel-cobalt alloys in the forms of wire, rod, bar, strip, sheet, and tubing, intended primarily for brazed metal-to-ceramic seals with alumina ceramics, for vacuum electronic applications. The two alloys covered here are UNS K94630 that contains nominally 29 % nickel, 17 % cobalt, and 53 % iron, and UNS K94620 that contains nominally 27 % nickel, 25 % cobalt and 48 % iron. When tested, the alloys shall comply to specified requirements for chemical composition, surface finish, temper, grain size, tensile strength, hardness, inclusion content, thermal expansion, transformation, and dimensions.