Looking for reliable CNC Gear Hobbing Invar? VT machining manufactures Invar parts to tight tolerances and consistent quality. Invar is ultra-low thermal expansion, so the process is set up specifically for the material.
CNC Gear Hobbing Capability for Invar
- Spur & helical gears
- Module range support
- Pre-grind accuracy
- High productivity
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 Hobbing 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.
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 Gear Hobbing 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.
Working with Invar
Invar is ultra-low thermal expansion. We translate those properties into a process plan: the right tooling, speeds, feeds and fixturing for the alloy.
Where the grade, temper or heat-treat condition matters to performance, we confirm it with you and can supply material certificates. Material is procured to recognised standards for consistent, repeatable results.
Design Tips for CNC Gear Hobbing Invar
Small design adjustments often cut cost and lead time. 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.
Secondary Operations & Finishing
Most Invar parts need some finishing, which we manage in-house or through vetted partners. Options include deburring and edge-breaking, heat treatment, surface grinding, polishing, and plating or anodising for corrosion resistance and appearance. Give us the finished-part requirement and we will sequence every operation correctly.
CNC Gear Hobbing Quality & Inspection
Quality is built in, not inspected on. We monitor key features during the run and confirm them at final inspection, with CMM verification available for tight tolerances. We provide the inspection and traceability records your quality system requires.
CNC Gear Hobbing 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.
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 Gear Hobbing Invar
Invar parts made this way are found throughout aerospace, medical, automotive, electronics and industrial equipment. Prototype, bridge and production volumes are all welcome.
How to Order CNC Gear Hobbing Invar
Starting your project takes one email. Send your CAD or 2D drawing, the Invar grade and condition, the quantity and any finish or inspection requirements. We respond quickly with price, lead time and any DFM notes, in clear English.
Parts We Have Run in Invar
Three representative CNC Gear Hobbing 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.
Internal ring gear
- Material
- Invar
- Size
- m2.5, z72, ID 190 mm
- Key callouts
- DIN 8, pitch deviation 0.03 mm
- Batch
- 150 pcs
Shaped rather than hobbed — an internal gear leaves no room for a hob to run out.
Worm and wheel set
- Material
- Invar
- Size
- m3, single start
- Key callouts
- Backlash 0.05–0.10 mm as a matched pair
- Batch
- 120 sets
Supplied as matched sets and marked, because mixing pairs loses the backlash spec.
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.
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 Hobbing 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 Hobbing
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 surface finish is achievable on Invar with CNC Gear Hobbing?
Surface finish on Invar is controlled to your specification; we confirm the achievable Ra against your callout.
Why is Invar a good choice for CNC Gear Hobbing?
Invar is ultra-low thermal expansion, which makes it well suited to CNC Gear Hobbing. We tune the process to the alloy so the finished Invar gear cutting part meets your dimensional and functional requirements.
How clean are the edges produced by CNC Gear Hobbing on Invar?
Machined Invar edges are clean and to specification; edge-break or deburring is added when your drawing calls for it.
Does CNC Gear Hobbing 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.