Ceramvar alloy or we call iron-nickel-cobalt alloys, nominally 27% nickel, 25% cobalt and 48% iron, 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. Unless otherwise indicated. 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