Kovar® is an iron-nickel-cobalt alloy engineered for one signature property: its thermal expansion matches borosilicate glass — which is why it is the material of choice for glass-to-metal seals in optical, electronic and vacuum packages. Machining it well starts with chemistry you can trust.
Kovar's expansion behavior depends on its Ni/Co balance. Every incoming batch is checked on our benchtop spectrometer against the specified grade — before it touches a machine.
±0.005 mm typical where applicable, surface finish down to Ra 0.2 µm — with tooling and parameters matched to tough, work-hardening Fe-Ni-Co.
EN 10204 3.1 certificates, batch traceability and Zeiss CMM dimensional reports — standard, not extras.
Real capability windows — verified in-house, not estimated.
| Capability | Specification |
|---|---|
| Material | Kovar® (Fe-Ni-Co glass-sealing alloy), grade verified per batch |
| Typical tolerance | ±0.005 mm typical where applicable · ±0.01 mm standard |
| Surface finish | Down to Ra 0.2 µm |
| Processes | CNC milling, turning, Swiss-type for small parts |
| Inspection | Zeiss CMM + spectrometer chemistry verification |
| Certificates | EN 10204 3.1 · batch traceability |
| Prototype lead time | Typically 5–10 working days |
A transparent, engineering-led process built for long-term supply programs — not one-off transactions.
Send drawings and program context. Our engineers run a DFM review and flag tolerances, materials and risk before any cutting begins.
You receive a transparent quote plus a material-verification plan — grade, EN/DIN check and certificate strategy for your application.
In-house precision machining, then Zeiss CMM dimensional inspection and spectrometer material verification on critical batches.
Kitted, ESD-safe or cleanroom packaging, with local engineering and after-sales support through our German partner.
Tell us about your program. The fields below help our engineering team prioritize recurring, long-term supply programs with equipment manufacturers.
Every critical dimension is verified on our in-house Zeiss CMM · material chemistry confirmed by spectrometer · EN 10204 3.1 certificates available.
Prefer email? Write to us directly at info@prototech-machining.com