VT machining provides CNC Engraving 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.
CNC Engraving Capability for Invar
- Depth control to 0.02 mm
- Fine fonts & logos
- Serial / data-matrix marking
- Conical and ball engravers
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 Engraving 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.
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 Engraving 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 Engraving Tolerances & Surface Finish
For CNC Engraving, 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.
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.
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.
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 Engraving 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.
Design Tips for CNC Engraving Invar
Small design adjustments often cut cost and lead time. 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 Engraving 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 Engraving 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 Engraving 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.
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.
Sensor housing
- Material
- Invar
- Size
- 86 × 54 × 22 mm
- Key callouts
- Pocket depth ±0.02 mm, bore H7, flatness 0.015 mm
- Batch
- 250 pcs / quarter
O-ring groove finished in the same setup as the sealing face so the two stay parallel.
Optical mount plate
- Material
- Invar
- Size
- 160 × 160 × 12 mm
- Key callouts
- Hole pattern true position ±0.02 mm, flatness 0.01 mm
- Batch
- 40 pcs
Roughed, stress-relieved overnight, then finished — the plate is too thin to hold flatness in one hit.
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 Engraving 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 Engraving
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 Engraving Invar?
CNC Engraving 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 Engraving Invar and how is it done?
CNC Engraving Invar refers to cNC engraving marks logos, text, serial data and fine detail by removing a controlled depth of metal. 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 tolerances can you hold for CNC Engraving 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.
How clean are the edges produced by CNC Engraving on Invar?
Machined Invar edges are clean and to specification; edge-break or deburring is added when your drawing calls for it.