CNC Swiss Machining Invar from VT machining delivers precision Invar parts produced to your exact drawing. Swiss-type machining guides bar stock through a sliding headstock for high-accuracy small, slender parts, and we tune every parameter to the behaviour of Invar, which is ultra-low thermal expansion.
Starting Parameters for CNC Swiss Machining Invar
| 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 Invar 36, the most common Invar grade we see for CNC Swiss Machining. Starting values for Invar 36, Annealed; optimised on the first article.
CNC Swiss Machining Capability for Invar
- Ø1–32 mm bar
- Slenderness without deflection
- Tolerance to ±0.003 mm
- High-volume small parts
Invar material properties, finishing options and grade notes are on our CNC Turning Invar page.
How CNC Swiss Machining Invar Works
The Invar 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.
Programming is driven directly by your 3D model or print. Work-holding, tool selection and the cutting strategy are planned around the critical features and the material before the first chip is cut. First-off inspection confirms the process is centred before production continues.
Achievable Tolerances for CNC Swiss Machining Invar
| 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.
CNC Swiss Machining Tolerances & Surface Finish
Turned Invar 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.
Exact achievable figures depend on the alloy, the feature size and the part geometry. Tell us which dimensions are critical and we will advise feasibility up front.
Design Tips for CNC Swiss Machining Invar
We are happy to suggest design tweaks that improve manufacturability. Consistent diameters, standard thread forms and avoiding extremely long, slender features help Invar turned parts stay concentric and economical. If you send your model early, we will return practical DFM feedback before you commit to production.
Applications of CNC Swiss Machining Invar
Customers order CNC Swiss Machining Invar components for everything from instrumentation to structural and functional assemblies. Whether you need a single prototype or recurring production volume, the same process discipline applies.
Typical Invar Parts for CNC Swiss Machining
Illustrative examples of CNC Swiss Machining Invar 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.
Connector pin
- Material
- Invar
- 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.
Threaded fitting
- Material
- Invar
- 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.
Precision shaft
- Material
- Invar
- Size
- Ø16 × 240 mm
- Key callouts
- OD h6, concentricity 0.01 mm TIR, keyway 5 H9
- Batch
- 1,000 pcs / year
Turned between centres so both journals share one datum.
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 Invar
- 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 Invar 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 Invar
Send the drawing, the Invar grade and the quantity. You get pricing, lead time and any DFM notes back — usually within one business day.
Request a QuoteFrequently Asked Questions
What is the typical lead time and minimum order for CNC Swiss Machining Invar?
CNC Swiss Machining prototypes for Invar can be produced quickly and scaled to series production. Send your drawing and quantity and we will advise lead time and any minimum order.
What is CNC Swiss Machining Invar and how is it done?
CNC Swiss Machining Invar refers to swiss-type machining guides bar stock through a sliding headstock for high-accuracy small, slender parts. Applied to Invar — ultra-low thermal expansion — VT machining produces each part to your CAD drawing, selecting parameters from your tolerance, finish and quantity requirements.
What surface finish is achievable on Invar with CNC Swiss Machining?
Surface finish on Invar is controlled to your specification; we confirm the achievable Ra against your callout.
Which industries use CNC Swiss Machining Invar parts?
CNC Swiss Machining Invar parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise Invar components are required.
How clean are the edges produced by CNC Swiss Machining on Invar?
Machined Invar edges are clean and to specification; edge-break or deburring is added when your drawing calls for it.