Kovar, also known as ASTM F 15 Alloy, is a controlled expansion alloy that is typically applied to high integrity glass and ceramic to metal seals, lids, lead frames and electronic package base. Kovar is made of nickel, cobalt and iron. This alloy is designed to adapt to computer, microwave, hydrid, semiconductor and space age technology demands, thus, making this an essential resource to the defense, aerospace and telecommunications industries.

National Electronic Alloys requires stringent vacuum melting processes that yield the highest level of cleanliness and a more homogenous alloy.  We source our products from only the top quality mills and require they test the material to exceed industry standards. Our ASTM F15 alloy (Kovar©) is extremely stable, passing standard Phase transformation tests of  -80°C, and remain stable down to – 196°C.

Kovar alloy is a vacuum melted, iron-nickel-cobalt, low expansion alloy whose chemical composition is controlled within narrow limits to assure precise uniform thermal expansion properties. Extensive quality controls are employed in the manufacture of this alloy to ensure uniform physical and mechanical properties for ease in deep drawing, stamping and machining.


Some of the typical applications of Kovar are listed below:

  • Kovar alloy has been used for making hermetic seals with the harder Pyrex glasses and ceramic materials.
  •  Power tubes,microwave tubes, transistors and diodes.
  • In intergrated circuits, it has been used for the flat pack and the dual-in-line package.

In Forms Of

Pipes & Tubes

Round Bars

Sheets Plates Coils


Pipe Fittings



Flat Bars

Filler Rods