Kovar (UNS K94610)
Kovar (UNS K94610, ASTM F15) is an iron–nickel–cobalt controlled-expansion alloy whose thermal expansion closely follows that of borosilicate glass and alumina ceramics. That match is what makes it the standard choice for hermetic glass-to-metal seals in electronic packages, vacuum tubes, microwave devices, sensor housings and semiconductor headers, where a mismatched seal would craze or leak through thermal cycling.
Available Forms
Equivalent Grades & Standards
| Property | Value |
|---|---|
| UNS number | K94610 |
| Coefficient of expansion (30-400 °C) | 4.60-5.20 µm/m·°C (Acceptance limit per ASTM F15 Section 11.1 - not a typical value) |
| Coefficient of expansion (30-450 °C) | 5.10-5.50 µm/m·°C (Acceptance limit per ASTM F15 Section 11.1 - not a typical value) |
Identifiers and physical constants for Kovar. A dash means no such designation is published for this grade.
Specifications by Product Form
Kovar (K94610) is supplied to a different standard in each form. Quote the one that matches the product you are ordering.
| Product form | Specification |
|---|---|
| Plate, sheet and strip | AMS 7728 |
| Rod and bar | ASTM F15 / AMS 7727 |
| Wire | ASTM F15 / AMS 7726 |
| Pipe and tube | ASTM F15 |
Aurico Alloys LLP supplies Kovar across the forms above, with material test certificates (EN 10204 3.1) and export-ready packaging from Mumbai, India. Contact us for stock availability and pricing.