CNC Gear Cutting Invar is a core capability at VT machining. We combine controlled gear cutting with material-aware setup for Invar — an alloy that is ultra-low thermal expansion — to produce parts that meet your specification first time.
CNC Gear Cutting Capability for Invar
- Multiple gear types
- Profile accuracy class
- Custom modules
- Hardened-blank ready
Invar Material Data
| Density | 8.11 g/cm³ |
|---|---|
| Tensile strength | 450–590 MPa |
| Yield strength (0.2%) | 275 MPa |
| Hardness | 130–160 HB |
| Melting point | 1427 °C |
| Thermal conductivity | 10.5 W/m·K |
| Thermal expansion | 1.2 (0–100 °C) ×10⁻⁶/K |
| Electrical conductivity | 2% |
| Machinability (C36000 = 100%) | 25% |
| Grades we run | Invar 36, Super Invar 32-5, Alloy 42, Alloy 46 |
Published typical values for Invar 36 (FeNi36). Other grades in the family differ — the certificate supplied with your order carries the actual heat-lot figures.
The low expansion is the whole point, so machining stress is the enemy. Rough, stress-relieve at 315–425 °C, then finish — otherwise the part moves after it leaves the machine.
How CNC Gear Cutting Invar Works
Tooth profiles are generated in the Invar blank by a synchronised cutter, then refined to the required accuracy class. Module, pressure angle and helix are programmed from your gear data.
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 Gear Cutting Invar
| Feature | Standard | Precision |
|---|---|---|
| Accuracy class | DIN 8 / AGMA 10 | DIN 6 / AGMA 12 |
| Profile deviation | 0.020 mm | 0.008 mm |
| Lead deviation | 0.020 mm | 0.008 mm |
| Pitch deviation (cumulative) | 0.040 mm | 0.015 mm |
| Runout | 0.030 mm | 0.010 mm |
| Tooth surface finish | Ra 1.6 µm | Ra 0.4 µm (ground) |
| Module range | m0.5–m8 | m1–m6 |
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.
Secondary Operations & Finishing
Finished Invar parts can move straight into secondary operations under one roof. Typical add-ons are deburring, passivation, anodising, plating, blasting, polishing and laser marking. We coordinate the whole chain so you receive complete, inspection-ready parts.
Design Tips for CNC Gear Cutting Invar
We are happy to suggest design tweaks that improve manufacturability. Providing complete gear data (module, pressure angle, profile shift, quality class) lets us produce Invar gears right the first time. If you send your model early, we will return practical DFM feedback before you commit to production.
CNC Gear Cutting Tolerances & Surface Finish
Gear features are produced to a specified DIN/AGMA accuracy class, with profile and lead controlled for quiet, durable running under load.
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.
CNC Gear Cutting Quality & Inspection
We control quality throughout the process, not just at the end. In-process checks plus final inspection — including CMM where specified — keep every Invar part to print. Inspection reports, material certificates and first-article documentation can be supplied on request.
Working with Invar
As a material, Invar is ultra-low thermal expansion. Our setup reflects the alloy's machinability so the finished part is accurate and free of avoidable defects.
We verify the exact grade and condition before machining, and traceable mill certs are available on request. We can work to your nominated material source or specification when required.
Applications of CNC Gear Cutting Invar
Customers order CNC Gear Cutting 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.
How to Order CNC Gear Cutting Invar
Getting a quote is simple. Share your model, the material grade, your quantity and target tolerances. You receive a clear quotation with lead time and honest manufacturability feedback.
Parts We Have Run in Invar
Three representative CNC Gear Cutting Invar 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.
Helical pinion
- Material
- Invar
- Size
- m1.5, z18, 15° helix
- Key callouts
- DIN 6, lead deviation 0.008 mm
- Batch
- 300 pcs
Ground after case hardening to 58 HRC at 0.6 mm case depth.
Splined shaft
- Material
- Invar
- Size
- DIN 5480, 26 × 1.5
- Key callouts
- Fit class H7/g6, runout 0.02 mm
- Batch
- 800 pcs
Spline hobbed with the journals ground afterwards on the same centres.
Bevel gear pair
- Material
- Invar
- Size
- m2, z20/z40, 90° axes
- Key callouts
- DIN 8, mounting distance ±0.03 mm
- Batch
- 200 sets
Contact pattern checked on a rolling tester before release.
Finishing Options for Invar
| 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 Gear Cutting 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 Gear Cutting
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
Does CNC Gear Cutting Invar require dedicated tooling?
Most Invar gear cutting 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 Gear Cutting?
Invar is ultra-low thermal expansion, which makes it well suited to CNC Gear Cutting. We tune the process to the alloy so the finished Invar gear cutting part meets your dimensional and functional requirements.
What surface finish is achievable on Invar with CNC Gear Cutting?
Surface finish on Invar is controlled to your specification; we confirm the achievable Ra against your callout.
What is the typical lead time and minimum order for CNC Gear Cutting Invar?
CNC Gear Cutting 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 tolerances can you hold for CNC Gear Cutting Invar?
Achievable tolerances for Invar gear cutting depend on the alloy, geometry and feature size. We hold tight, repeatable tolerances appropriate to the feature and material. Exact figures are confirmed against your drawing callouts.