Product Description

4J29 alloy rod, also known as Kovar rod, is a Fe-Ni-Co controlled expansion alloy with a thermal expansion coefficient closely matching that of hard glass and ceramics. It provides excellent glass-to-metal and ceramic-to-metal sealing properties, ensuring reliable hermeticity.

With stable mechanical performance, good machinability, and outstanding sealing reliability, 4J29 rods are widely applied in electronic packaging, vacuum devices, semiconductor bases, sensors, and aerospace instruments.

Key Features

• Fe-Ni-Co controlled expansion alloy

• Thermal expansion matches hard glass and ceramics

• Excellent hermetic sealing performance

• Stable mechanical strength at different temperatures

• High machinability and surface finish

• Available in rods, wires, sheets, and customized forms

Typical Applications

• Glass-to-metal hermetic sealing

• Semiconductor packaging bases

• Electronic packaging components

• Vacuum tubes and light bulbs

• Aerospace and defense devices

• Sensors, relays, and feedthroughs