Industry
Invar and Kovar Machining for Medical Device Manufacturers
Medical device engineers use Kovar for hermetic feedthroughs and seal packages and Invar 36 for calibration-critical diagnostic components. We are a matching service, not a shop: send your drawing and we connect you with up to three vetted shops who quote you directly.
Why Medical Device Manufacturing programs specify these alloys
Medical electronics use Kovar where a pin or a window has to cross a sealed wall without breaking hermeticity, in feedthroughs, seal rings and connector housings, because its expansion tracks borosilicate glass and alumina through the sealing cycle and through sterilization and storage. Diagnostic and lab equipment manufacturers use Invar 36 for a different reason entirely: an optical bench, an imaging alignment structure or a lab automation stage holds its calibration only if its geometry does not drift with ordinary room temperature swings, and Invar 36 moves roughly a tenth as much as aluminum over the same range.
None of that makes a raw alloy medical grade, implant grade or biocompatible. Those properties belong to the finished, tested device and to the manufacturer’s own design validation and quality system, not to a machined component. We do not manufacture devices, and we do not claim that this site or any matched shop holds FDA registration, FDA clearance, ISO 13485 certification or any other regulatory or quality credential.
What a buyer sourcing for a regulated device should focus on is verifiable: material traceability back to the mill certificate, documented process and change control, and a quality system whose scope and current certificate you request and check yourself before releasing production parts.
Where Medical Device Manufacturing uses Invar, Kovar and Alloy 42
Hermetic feedthroughs
Kovar bodies carrying pins through a glass or ceramic insulator into implantable electronics such as pacemaker and neurostimulator headers.
Seal rings and housings
Kovar rings, eyelets and sensor housings that braze or glass-seal for hermetic medical electronics packaging.
Diagnostic and lab equipment components
Invar 36 optical benches, imaging alignment structures and lab automation stage parts where calibration accuracy depends on dimensional stability, not implantation.
Supplier verification
Buyers request and independently confirm a candidate shop’s quality system, traceability and change control before committing a regulated-device drawing.
What to put on the RFQ, and what to vet in a supplier
We match your RFQ. You still own supplier qualification. These lines get you a comparable quote and a shop that can answer the qualification questions your program asks.
State the alloy and spec (Kovar per ASTM F15, Invar 36 per ASTM F1684) and the delivery condition, machined only or process-ready for sealing.
Call out seal features, leak rate, insulation resistance or calibration-critical tolerances explicitly, not just the machined dimensions.
Request the shop’s current quality certificate, if any, and its scope statement, and verify both directly rather than trusting a website logo.
Ask about material traceability, lot record retention and how the shop notifies you of a material or process change.
Never assume this site or a matched shop’s participation implies FDA registration, FDA clearance or ISO 13485 certification; confirm any such status yourself.
State your device’s risk classification internally so your own quality function sets the right bar before the RFQ goes out.
Medical Device Manufacturing guides
- Materials
Kovar Feedthroughs for Implantable Medical Electronics
How Kovar hermetic feedthroughs seal pins into implantable electronics, what to specify on the drawing and why certification stays the device maker's job.
- Process
Kovar Seal Rings for Medical Device Hermetic Packages
Machining and surface prep for Kovar seal rings and housings in medical packaging: cleanliness before sealing and the dimensional control that holds a seal.
- Materials
Invar Parts for Diagnostic and Lab Equipment Manufacturers
Invar 36 machining for diagnostic imaging, lab automation and analyzer components, where dimensional stability protects calibration accuracy over temperature.
- Choosing a Supplier
What Medical Device Buyers Should Require from a Machining Supplier
A verification checklist for medical device buyers sourcing Invar or Kovar parts: quality system documents, traceability and change control to check yourself.
- Materials
Machining Kovar for Glass to Metal Seals: What the Seal Needs
Kovar glass to metal seal machining: why ASTM F15 Kovar matches borosilicate glass, how it machines, the anneal and oxide steps before sealing and the RFQ.
- Choosing a Supplier
Invar Mill Certifications: What a Certified Material Report Should Show
What a standard Invar 36 or Kovar mill cert includes, when to ask for measured CTE data, and how to read a certified material test report before it reaches your shop.
- Choosing a Supplier
Second-Source Qualification: Requalifying an Invar Part at a New Shop
What changes when you move an existing Invar part to a second machine shop: process differences to check, first article comparison and what to document.
Alloy pages: Invar 36 machining, Super Invar machining, Kovar machining, Alloy 42 machining. Spec numbers and CTE by temperature band on the Invar specs reference.
Have a drawing ready?
Send the short version now. We will ask for anything missing. For full details up front use the full RFQ form. Reply within 24 business hours.
Your files go only to the shops we match. Ask for an NDA and nothing is shared until it is signed.
Questions from Medical Device Manufacturing buyers
Something else? Email .
Are your matched shops FDA registered or ISO 13485 certified?
We do not certify shops and do not claim that this site or any matched shop holds FDA registration, FDA clearance, ISO 13485 certification or any other regulatory or quality credential. If certification matters to your program, request the shop’s certificate and scope directly and verify it with the issuing body yourself.
Does using Kovar or Invar 36 make a part medical grade or biocompatible?
No. Biocompatibility and any regulatory clearance are properties of the finished, tested device and the manufacturer’s own quality system, not of a raw alloy. A machined Kovar or Invar 36 part is a component; qualifying it for a specific device is the device manufacturer’s responsibility.
What is the difference between Kovar and Invar 36 for medical applications?
Kovar is chosen when a part must seal to glass or ceramic, matched to their expansion, as in feedthroughs and seal rings. Invar 36 is chosen for the lowest expansion near room temperature, used in diagnostic and lab equipment components where calibration stability matters and no glass seal is involved.
Do you manufacture or certify medical device parts?
No. We are a matching service. We connect your RFQ with up to three shops experienced in Kovar or Invar 36 for the relevant application, and you place the order, qualify the supplier and manage regulatory responsibility directly.