Due to the presence of corrosion-resistant elements such as nickel and cobalt, iron nickel cobalt alloys have good corrosion resistance and are suitable for working in harsh environments such as high temperatures, high pressures and corrosive media.

Iron-nickel-cobalt alloys 4j29/Kovarare suitable for magnetic application due to the presence of magnetic elements such as iron and nickel.

FeNiCo Alloy 4j29/Kovar has a coefficient of thermal expansion similar to that of hard (borosilicate) glass which makes it especially suitable in the electronics industry for metal parts bonded to hard glass envelopes for such devices as power tubes, x-ray tubes, etc, and other applications requiring glass-to-metal seals.