City Special Metals manufactures a variety of Kovar Alloy Products, including Kovar Plates, Bars, and Sheets. As well as Kovar, we are also widely known as Europe’s largest stockist of low and controlled expansion alloys. Discuss your requirements by contacting our team today.
City Special Metals stock and supply a wide range of kovar products and materials. Therefore, it should be no surprise that we know a lot about Alloy K too.
Head over to our insights pages if you’d like to read more about Kovar. We’ve written features about the Machinability of Kovar®, plus much more.
Ready to enquire with City Special Metals? We’re a leading UK based speciality metals stockist and always happy to help. Skip to our contact form below, fill in some details and also tell us about your Kovar Material Requirements requirements. Click here to skip down the page.
Our Products
Kovar alloy is a nickel-iron-cobalt, controlled expansion alloy. Its expansion characteristics match both borosilicate (or Pyrex) glasses and alumina ceramics. This alone ensures it is a highly popular controlled expansion alloy for hermetic sealing applications (also known as Glass to Metals Sealing).
| Product Form | Range From | Range To | |
|---|---|---|---|
 | Kovar Plate | 4mm | 210mm |
 | Kovar Round Bar | 4mm | 160mm |
 | Kovar Sheet & Coil | 0.025mm | 3.175mm |
 | Kovar Wire | 0.1mm | 3.175mm |
 | Kovar Tube | 3.175×0.254mm | 25.4×1.0mm |
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Beneficial Properties
- Expansion Control
Reliable hermetic sealing applications - Uniformity
Precise and uniform thermal expansion characteristics - Shock-resistant
Their coefficient thermal expansion makes the seal resistant to shock and cracking
Applications
- Hermetic Sealing
- Electronic tubes (power, X-Ray)
- Hybrid circuit casings
- Oscillator housings
- Concentrated solar power
- Scientific instruments
Markets
- Aerospace
- Solar
- Scientific
- Electronic
Kovar Chemistry
| Mechanical Properties | ||
|---|---|---|
| Metallurgical Condition | Annealed, Descaled | |
| Yield Strength | KSI (MPa) | 40 (276) |
| Tensile Strength | KSI (MPa) | 75 (518) |
| Hardness | HB | 78 |
| Elongation | 50mm | >20 |
| Co Efficient of Thermal Expansion | ||
|---|---|---|
| 30-300°C | 10-6/°C | 5 |
| 30-400°C | 10-6/°C | 5.15 |
| Density | g/cm³ | 8.26 |
| Curie Temp | °F (°C) | 815 (435) |
| Melting Point | °F (°C) | 2640 (1449) |
| Modulus of Elasticity at 20°C | MPa | 207 |
| Specific Heat | J/g- °C | 0.11 |
| Thermal Conductivity at 20°C | W/m.k | 17.3 |
| Thermal Expansion | W.m-¹°C | 0.17 |
| Electrical Resistivity | mm²/m | 49 |
| Poisson’s coefficient | 0.317 |
| Technical Specifications | |||
|---|---|---|---|
| ASTM | UNS | Workstoff | AMS |
| F15 | K94610 | 1.3981 | I-23011 CL1 |
| Chemistry | ||
|---|---|---|
| Nickel | Ni | 29 |
| Cobalt | Co | 17 |
| Iron | Fe | Balance |
| Manganese | Mn | 0.5 |
| Silicon | Si | 0.2 |
| Carbon | C | 0.04 |
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We can distribute metals across the globe, including locations in Europe, The Middle East, The Far East and the Americas.
Phone Us
+44 1268 774 261
Speak to the Sales Team
sales@cityspecialmetals.com
Ask Us A Question
info@cityspecialmetals.com
More about Kovar
Kovar has been in use for many decades as a controlled expansion alloy. However, despite its relatively long history, many people outside the engineering industry have never heard of Kovar.
What makes Kovar so unique is it’s coefficient of thermal expansion. As a controlled expansion alloy, it shared some remarkable similarities to borosilicate glass (hard glass) and ceramic.
Kovar’s coefficient of thermal expansion is not an accident, though. Going back in history, Kovar was carefully formulated to meet a specific need. In 2019 and beyond, City Special Metals serve to manufacture Kovar to the highest standard. You can learn more about our Quality Assurances here.
Kovar is also known by the following trade names:
- Kovar®
- Pernifer 29-18®
- Dilaton 29-18® Dilver P®
- Dilver® NiCoFe®
- Telcoseal 1®
- Sealvar®
- Nilo K®
- Nicoseal®
- Nicosel®
- Therlo®
- FeNi29Co17®
