VT machining provides CNC Swiss Machining Kovar for customers who need accurate, repeatable Kovar components. Because Kovar is matched thermal expansion for glass/ceramic seals, we adapt the process to suit — controlling the variables that matter for this alloy.
Starting Parameters for CNC Swiss Machining Kovar
| Cutting speed (carbide) | 35-80 m/min |
|---|---|
| Feed | 0.06-0.18 mm/rev |
| Spindle speed, Ø8 mm bar | 1390-3180 rpm |
| Insert / tool class | ISO S — sharp PVD-coated carbide |
| Coolant | Flood emulsion; sulphurised oil for tapping |
| Length-to-diameter capability | up to ~10:1 (slower feeds for this grade) |
Shown for Kovar, the most common Kovar grade we see for CNC Swiss Machining. Starting values for Kovar, Annealed; optimised on the first article.
CNC Swiss Machining Capability for Kovar
- Ø1–32 mm bar
- Slenderness without deflection
- Tolerance to ±0.003 mm
- High-volume small parts
Kovar material properties, finishing options and grade notes are on our CNC Turning Kovar page.
How CNC Swiss Machining Kovar Works
The Kovar bar or billet rotates in the spindle while single-point tools shape outer diameters, bores, faces, grooves and threads. Constant surface speed control keeps cutting conditions stable from large to small diameters.
We start from your supplied geometry and tolerance scheme. The setup is designed to minimise re-clamping, which protects positional accuracy across features. A first article is verified against the drawing before the balance of the batch is released.
Achievable Tolerances for CNC Swiss Machining Kovar
| Feature | Standard | Precision |
|---|---|---|
| Outside diameter | ±0.05 mm | ±0.005 mm |
| Bore diameter | H9 | H6 |
| Length / shoulder position | ±0.10 mm | ±0.020 mm |
| Concentricity OD to ID | 0.05 mm TIR | 0.010 mm TIR |
| Roundness | 0.02 mm | 0.005 mm |
| Thread class | 6g / 2A | 4h / 3A |
| Surface finish, as turned | Ra 1.6 µm | Ra 0.4 µm |
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.
Design Tips for CNC Swiss Machining Kovar
Small design adjustments often cut cost and lead time. Consistent diameters, standard thread forms and avoiding extremely long, slender features help Kovar turned parts stay concentric and economical. If you send your model early, we will return practical DFM feedback before you commit to production.
CNC Swiss Machining Tolerances & Surface Finish
Turned Kovar holds diameter tolerances to about ±0.005 mm with concentricity within 0.01 mm and good roundness. Turned finishes of Ra 0.4–0.8 µm are achievable with finishing passes and sharp tooling.
The tightest tolerances are reserved for the features your drawing flags as critical. Share your tolerance scheme and we will confirm what is realistic before quoting.
Applications of CNC Swiss Machining Kovar
Kovar parts made this way are found throughout aerospace, medical, automotive, electronics and industrial equipment. Prototype, bridge and production volumes are all welcome.
Typical Kovar Parts for CNC Swiss Machining
Illustrative examples of CNC Swiss Machining Kovar parts and the callouts that usually drive the process plan. They show the kind of work that fits this process; they are not specific customer orders.
Threaded fitting
- Material
- Kovar
- Size
- Ø22 hex × 38 mm
- Key callouts
- G3/8" thread class 4h, bore H8, sealing face Ra 0.8 µm
- Batch
- 2,500 pcs
Run on a sub-spindle lathe so the back face is finished without a second setup.
Connector pin
- Material
- Kovar
- Size
- Ø3.0 × 24 mm
- Key callouts
- OD ±0.005 mm, straightness 0.02 mm over length
- Batch
- 20,000 pcs
Swiss-turned from bar with a guide bushing; nothing else holds Ø3 mm over 24 mm.
Valve seat
- Material
- Kovar
- Size
- Ø28 × 14 mm
- Key callouts
- Seat angle 45° ±0.1°, roundness 0.005 mm, Ra 0.2 µm
- Batch
- 800 pcs
Seat finished with a single-point diamond pass, no interruption.
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 Swiss Machining 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 Swiss Machining
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
Can VT machining make custom Kovar parts to my drawing?
Yes. Kovar turning 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.
Why is Kovar a good choice for CNC Swiss Machining?
Kovar is matched thermal expansion for glass/ceramic seals, which makes it well suited to CNC Swiss Machining. We tune the process to the alloy so the finished Kovar turning part meets your dimensional and functional requirements.
What tolerances can you hold for CNC Swiss Machining Kovar?
Achievable tolerances for Kovar turning depend on the alloy, geometry and feature size. Turning holds diameter tolerances to around ±0.005 mm with concentricity within 0.01 mm. Exact figures are confirmed against your drawing callouts.
What surface finish is achievable on Kovar with CNC Swiss Machining?
Surface finish on Kovar is controlled to your specification; we confirm the achievable Ra against your callout.