VT machining provides CNC Broaching Invar for customers who need accurate, repeatable Invar components. Because Invar is ultra-low thermal expansion, we adapt the process to suit — controlling the variables that matter for this alloy.
Process Data for CNC Broaching Invar
| Broaching speed (HSS-E) | 2.4-4.8 m/min |
|---|---|
| Rise per tooth | 0.02-0.04 mm |
| Lubricant | Sulphurised broaching oil |
Shown for Invar 36, the most common Invar grade we see for CNC Broaching. Typical values for Invar 36, Annealed; confirmed on the first part.
CNC Broaching Capability for Invar
- Keyways & splines
- Internal profiles
- One-pass forming
- High repeatability
Invar material properties, finishing options and grade notes are on our CNC Milling Invar page.
How CNC Broaching Invar Works
Rotating multi-flute cutters remove material as the Invar workpiece is driven through programmed tool paths on 3-, 4- or 5-axis machining centres. Climb milling, step-over and depth-of-cut are set so chip load stays in the ideal band for the alloy.
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 Broaching Invar
| Feature | Standard | Precision |
|---|---|---|
| Linear dimension (< 100 mm) | ±0.05 mm | ±0.010 mm |
| Linear dimension (100–300 mm) | ±0.10 mm | ±0.025 mm |
| Hole diameter (reamed) | H9 | H7 |
| True position of hole pattern | ±0.10 mm | ±0.025 mm |
| Flatness over 100 mm | 0.05 mm | 0.015 mm |
| Perpendicularity | 0.10 mm | 0.020 mm |
| Surface finish, as machined | 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 Broaching Tolerances & Surface Finish
For CNC Broaching, dimensional and positional tolerances around ±0.01 mm are routine, tightening toward ±0.005 mm on precision setups. Surface finish on machined faces typically falls in the Ra 0.4–1.6 µm range depending on tooling and pass strategy.
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 Broaching Invar
We are happy to suggest design tweaks that improve manufacturability. Generous internal radii, sensible pocket depth-to-width ratios and avoiding very thin unsupported walls all reduce cost and improve accuracy in Invar. If you send your model early, we will return practical DFM feedback before you commit to production.
Applications of CNC Broaching Invar
Customers order CNC Broaching 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 Broaching
Illustrative examples of CNC Broaching 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.
Heat sink base
- Material
- Invar
- Size
- 200 × 100 × 8 mm
- Key callouts
- Fin thickness 1.2 ±0.05 mm, base flatness 0.03 mm
- Batch
- 500 pcs
Fins cut with a slotting cutter in one pass to avoid the deflection a step-over leaves.
Manifold block
- Material
- Invar
- Size
- 120 × 60 × 45 mm
- Key callouts
- Cross-bore intersection ±0.05 mm, ports G1/8", leak-tested to 10 bar
- Batch
- 80 pcs
Deburred internally with a brush tool; a burr at a cross-bore is what fails the leak test.
Robot end-effector bracket
- Material
- Invar
- Size
- 180 × 90 × 30 mm
- Key callouts
- Bore pair concentric within 0.02 mm, weight reduction pockets
- Batch
- 120 pcs
Pockets ganged so wall thickness never drops below 2 mm at the load path.
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 Broaching 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 Broaching
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 tolerances can you hold for CNC Broaching Invar?
Achievable tolerances for Invar machining depend on the alloy, geometry and feature size. Milling holds positional and dimensional tolerances to around ±0.01 mm, tighter with precision setups. Exact figures are confirmed against your drawing callouts.
Does CNC Broaching Invar require dedicated tooling?
Most Invar machining work uses standard cutting tools and CNC programs; dedicated fixtures are made only when geometry or volume requires them.
Why is Invar a good choice for CNC Broaching?
Invar is ultra-low thermal expansion, which makes it well suited to CNC Broaching. We tune the process to the alloy so the finished Invar machining part meets your dimensional and functional requirements.
Can VT machining make custom Invar parts to my drawing?
Yes. Invar machining 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.
Which industries use CNC Broaching Invar parts?
CNC Broaching Invar parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise Invar components are required.