Ferro-nickel

KOVAR

FeNi29Co17

UNS K94610

Kovar is a controlled-expansion alloy composed of iron (~54%), nickel (29%), and cobalt (17%). Its specific composition gives it its most valuable property: a very low coefficient of thermal expansion (~5.3 × 10⁻⁶/K), which closely matches that of borosilicate glass and certain ceramics. As a result, it is indispensable for creating reliable glass-to-metal and ceramic-to-metal hermetic seals in the electronics, aerospace, and medical industries.

Properties

Machinability
Magnetic properties
Resistance to high temperatures

Development

BIOLOGY STANDARD

States

BIOLOGY STANDARD

Applications

Mass-production applications
Glass-to-metal seals

Chemical Composition

ElementNeither (%)Fe (%)Co (%)
Contents29.054.017.0

Mechanical Properties

Rm (MPa)≥520
0.2 Rp (MPa)≥340
A%≥42
Density (g/cm³)8.2

Available Sizes

Standards

ASTM F15
AMS 7726
AMS 7727
AMS 7728

Certificate 3.1 available

Upon request when ordering

* These values are for reference only; they may vary depending on the standard and condition.