Kovar Controlled Expansion Alloy Hot Forged Round Bar for Glass Sealing Application

A-ONE ALLOY keeps in stock Kovar hot fogerd round bar from diameter 20mm to diameter 300mm. And we could make fast delivery for customized sizes as well as forged pieces.

Kovar controlled expansion alloy, most likely know as 4J29 in China, is a Nickel Iron alloy with 29% Nickel, 17% Cobalt and the remaining balance is Iron.

Kovar controlled expansion alloy, was invented to meet the need for a reliable glass-to-metal seal, which is required in electronic devices such as light bulbs, vacuum tubes, cathode ray tubes, and in vacuum systems in chemistry and other scientific research area.

Kovar has thermal expansion similar to glass. Meanwhile its nonlinear thermal expansion curve can often be made to match a glass. This makes it the most popular controlled expansion alloy so far.

Chemical compostion of Kovar

The average linear expansion coefficient(10^-6C)

Applications of Kovar

• Light bulbs
• Vacuum tubes
• Cathode ray tubes
• Power tubes
• Microwave tubes
• Transistoers
• Diodes
• Hybrid packages
• Other kinds of scientific instruments

Forms available at A-ONE ALLOY

• Bar
• Tube
• Strip
• Wire
• Plate
• Capillary

Suzhou Xunshi New Material Co., Ltd (refered as Xunshi afterwards) is a professional supplier of high performance alloys. Our factory is specialized in manufacturing Nickel alloys & Cobalt alloys for 10⁺ years，with a company mission to provide a high quality, reliable source for precision alloys, high temperature alloys and stainless steels in both pilot run and mass production. We are professionally manufacturing materials with unique features, which are then used in aerospace, military, electronics, marine, petroleum and petrochemical industries.

Base on “Quality-oriented, Leading Technology, Continuous Improvement, Customer Satisfaction”, we believe Xunshi could be your best supplier.

Product Scope of Xunshi

· Inconel

· Hastelloy

· Incoloy

· Monel

· Nimonic

· Nitronic

· Haynes

· Special Stainless Steel

· Soft Magnetic Alloy

· Permanent Magnetic Alloy

· Elastic Alloy

· Controlled Expansion Alloy

· Magnetostrictive Material

Services of Xunshi

· Material selection

· Non-standard product research and pre-production

· Hard to find material sourcing

· Cutting/splitting

· Precision machining

· Heat treatment

· Customized Packing

· Logistics service

Advantages of Xunshi

· Experienced in industry

· Quality control system

· Authorized Certificates

· Guaranteed delivery and quality

· Customers from 30+ countries trust us

Xunshi is engaged in introducing China-origin high performance alloys to the entire world. Choose Xunshi, choose high performance.