Product Specifications


AM ASTM F15 (Kovar) is a specialty alloy used to join metal to glass.  This is due to its thermal expansion properties, which are essentially the same as borosilicate glass.  This allows the two materials to heat and cool at the same rate, which helps ensure a good seal will form.  Typical applications include light bulbs, cathode ray tubes, and vacuum tubes. 




Forms Available

Wire, Foil, and Preformed shapes; rings, washers, discs, shims, specialty shapes. Two dimensional shapes can be Laser-cut and/or machined with EDM. Preforms must be cleaned prior to brazing.


Compare With:

  • UNS: K94610 
  • Fernico 1



  • Ni: 29%
  • Co: 17%
  • Fe: 54%