Product Details
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
Alloy | % | Ni | Cr | Co | Cu | C | Mn | Si | P | S | Mo | Fe |
Kovar | Min | 28.5 | | 16.8 | | | | | | | | Rem |
Max | 29.5 | 0.2 | 17.8 | 0.20 | 0.03 | 0.50 | 0.30 | 0.02 | 0.02 | 0.20 |
The average linear expansion coefficient(10-6C)
20~100°C | 20~300°C | 20~400°C | 20~450°C | 20~500°C | 20~530°C | 20~600°C |
— | — | 4.6~5.2 | 5.1~5.5 | — | — | — |
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
Company Profile
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.



