Looking for reliable CNC Polishing Kovar? VT machining manufactures Kovar parts to tight tolerances and consistent quality. Kovar is matched thermal expansion for glass/ceramic seals, so the process is set up specifically for the material.
CNC Polishing Capability for Kovar
- Mirror finish capable
- Ra to 0.05 µm
- Cosmetic & sealing faces
- Multi-stage abrasives
Kovar Material Data
| Density | 8.36 g/cm³ |
|---|---|
| Tensile strength | 517 MPa |
| Yield strength (0.2%) | 340 MPa |
| Hardness | 140–160 HV |
| Melting point | 1450 °C |
| Thermal conductivity | 17.3 W/m·K |
| Thermal expansion | 5.1 (30–200 °C) ×10⁻⁶/K |
| Electrical conductivity | 3.5% |
| Machinability (C36000 = 100%) | 35% |
| Grades we run | Kovar / ASTM F15, Alloy 42, Alloy 52 |
Published typical values for Kovar (ASTM F15). Other grades in the family differ — the certificate supplied with your order carries the actual heat-lot figures.
Sealing surfaces must stay clean. Parts destined for glass-to-metal seals are degreased and handled without bare hands after final machining.
How CNC Polishing Kovar Works
Abrasive media or tooling refine the Kovar surface in controlled stages, removing the previous step's marks until the target roughness and edge condition are reached.
Every job begins from your CAD model or 2D drawing. Fixturing and tool paths are planned so the most critical dimensions are produced in the most rigid, repeatable setup. Critical dimensions are checked on the first part and monitored through the run.
Achievable Tolerances for CNC Polishing Kovar
| Feature | Standard | Precision |
|---|---|---|
| Surface roughness | Ra 0.8 µm | Ra 0.05 µm |
| Edge break | 0.1–0.3 mm | 0.05 ±0.02 mm |
| Material removed | 0.02 mm | 0.005 mm |
| Bore roundness after honing | 0.005 mm | 0.002 mm |
| Cross-hatch angle | 45° ±10° | 45° ±5° |
| Cosmetic grade | uniform satin | mirror, no visible lines |
| Masking of datum faces | on request | standard |
Standard is what a normal quotation assumes. Precision is available on nominated features and is priced separately, because it needs extra setups, in-process gauging and CMM verification. Call out only the features that need it — blanket-tightening a drawing is the single most common reason a quote comes back expensive.
CNC Polishing Tolerances & Surface Finish
Finishing brings Kovar to a defined roughness target — from a uniform satin to Ra values as low as 0.05 µm — with controlled, repeatable edge breaks.
Final tolerances are governed by the material's behaviour, wall thickness and overall stiffness. We give honest DFM feedback if a callout would be costly or better achieved another way.
Design Tips for CNC Polishing Kovar
A few design choices make a real difference to cost and quality. Telling us the target Ra, the cosmetic faces and any masking needs lets us finish Kovar efficiently without over-processing. If you send your model early, we will return practical DFM feedback before you commit to production.
CNC Polishing Quality & Inspection
Consistent quality comes from disciplined process control. Critical dimensions on Kovar parts are checked in-process and verified at final inspection using calibrated instruments and, where required, CMM measurement. Full documentation — dimensional reports, mill certs, FAIR — is available when your programme needs it.
Working with Kovar
Kovar offers a useful combination of properties: it is matched thermal expansion for glass/ceramic seals. Those characteristics shape how we approach finishing — from tool and parameter selection to work-holding and coolant.
If your application is sensitive to alloy condition, we agree the specification in writing and document it. Stock is sourced from reputable suppliers so what you order is what you receive.
Secondary Operations & Finishing
We complete Kovar components with the secondary steps your drawing calls for. We arrange heat treatment, surface treatment, marking and assembly as needed. Tell us the final spec and we will plan the full route so parts arrive ready to use.
Applications of CNC Polishing Kovar
CNC Polishing of Kovar supports parts across aerospace, medical, automotive, electronics, semiconductor, energy and general industrial sectors. We scale from one-off prototypes to ongoing production while holding the same quality.
How to Order CNC Polishing Kovar
Ordering Kovar parts is straightforward. Provide the drawing, material, quantity and any certification needs. Our engineers reply — in English — with feasibility, pricing and a realistic lead time, usually within one business day.
Parts We Have Run in Kovar
Three representative CNC Polishing Kovar jobs, with the callouts that actually drove the process plan. Yours will differ — these are here so you can judge whether your part is in our range before you spend time on an RFQ.
Hydraulic bore
- Material
- Kovar
- Size
- Ø32 × 200 mm
- Key callouts
- Ra 0.4 µm cross-hatch 45°, roundness 0.003 mm
- Batch
- 600 pcs
Honed in three stages; the cross-hatch is what holds the oil film.
Passivated stainless fitting
- Material
- Kovar
- Size
- Ø18 × 40 mm
- Key callouts
- ASTM A967 citric passivation, no free iron
- Batch
- 5,000 pcs
Passivated after all machining, then tested with a copper sulphate check.
Mirror-polished insert
- Material
- Kovar
- Size
- 80 × 50 mm cavity
- Key callouts
- Ra 0.05 µm, SPI A2
- Batch
- 60 pcs
Polished in five abrasive stages; skipping one leaves scratches the next cannot remove.
Finishing Options for Kovar
| Finish | Thickness / effect | Why it gets specified |
|---|---|---|
| Deburr / edge break | 0.05–0.3 mm | All parts unless the drawing says otherwise |
| Bead blast | Ra 1.6–3.2 µm | Uniform matt finish, hides tool marks |
| Laser marking | — | Part number, lot code, data matrix |
No drawing yet? Build one in the browser.
Set the metal, dimensions and features, watch the 3D model update as you type, then switch to the 2D sheet to add dimensions and tolerances. Download it or send it straight to us with your RFQ.
What We Need to Quote CNC Polishing Kovar
- GeometrySTEP or IGES for the 3D model, plus a PDF drawing if you have tolerance callouts. A dimensioned sketch is enough to start.
- MaterialThe exact Kovar grade and condition — temper, heat-treat state or hardness. If you are not sure, tell us the function and we will suggest one.
- QuantityPrototype count and the expected annual volume. Both change how the part is made and therefore what it costs.
- TolerancesWhich features are critical. Everything else runs to our standard tolerance, which is what keeps the price sensible.
- FinishSurface treatment, cosmetic requirements, and any faces that must be masked.
- DocumentsWhether you need a material certificate, dimensional report, FAIR or PPAP with the shipment.
Missing something from the list is not a problem — send what you have. We will come back with the specific questions rather than a generic form.
Other Metals for CNC Polishing
Other Processes for Kovar
Send the drawing, the Kovar grade and the quantity. You get pricing, lead time and any DFM notes back — usually within one business day.
Request a QuoteFrequently Asked Questions
Which industries use CNC Polishing Kovar parts?
CNC Polishing Kovar parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise Kovar components are required.
Why is Kovar a good choice for CNC Polishing?
Kovar is matched thermal expansion for glass/ceramic seals, which makes it well suited to CNC Polishing. We tune the process to the alloy so the finished Kovar finishing part meets your dimensional and functional requirements.
What material thickness or size range suits CNC Polishing Kovar?
We machine Kovar across a broad size range; share your part envelope for confirmation.
Can VT machining make custom Kovar parts to my drawing?
Yes. Kovar Kovar finishing is made to order from your CAD/2D drawing. Share your geometry, material grade, tolerance and quantity and we will confirm feasibility, lead time and pricing.
How clean are the edges produced by CNC Polishing on Kovar?
Our deburring leaves Kovar with a consistent, controlled edge break and burr-free surfaces.
Does CNC Polishing Kovar require dedicated tooling?
Most Kovar finishing work uses standard cutting tools and CNC programs; dedicated fixtures are made only when geometry or volume requires them.