CNC Plasma Cutting Invar is a core capability at VT machining. We combine controlled 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 Plasma Cutting Capability for Invar
- Plate to 30+ mm
- High cutting speed
- Conductive metals
- Bevel-cut capable
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 Plasma Cutting Invar Works
A focused fibre-laser beam melts and blows material from the Invar sheet along the programmed contour. Power, focal position, nozzle stand-off and assist-gas pressure are tuned to the alloy and thickness for a clean, square edge.
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 Plasma Cutting Invar
| Feature | Standard | Precision |
|---|---|---|
| Contour dimension | ±0.10 mm | ±0.05 mm |
| Hole diameter | ±0.10 mm | ±0.05 mm |
| Kerf width | 0.20 mm | 0.10 mm |
| Squareness of cut edge | 0.5° | 0.2° |
| Heat-affected zone | 0.15 mm | 0.05 mm (N₂ assist) |
| Minimum hole diameter | 1.2 × thickness | 1.0 × thickness |
| Edge condition | light dross | burr-free, N₂ cut |
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.
CNC Plasma Cutting Tolerances & Surface Finish
Laser-cut Invar holds contour tolerances around ±0.05 mm depending on thickness, with a narrow kerf and a clean, near burr-free edge.
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.
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.
Design Tips for CNC Plasma Cutting Invar
Small design adjustments often cut cost and lead time. Keeping holes no smaller than the material thickness, allowing for kerf, and grouping features sensibly improves edge quality and nesting yield on Invar. If you send your model early, we will return practical DFM feedback before you commit to production.
CNC Plasma Cutting 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.
Applications of CNC Plasma Cutting 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 Plasma Cutting 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 Plasma 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.
Gasket / shim set
- Material
- Invar
- Size
- Ø120 × 0.5 mm
- Key callouts
- ID/OD ±0.05 mm, no heat discolouration
- Batch
- 3,000 pcs
Small-diameter holes below 1.2 × thickness are punched, not lased.
Machine guard panel
- Material
- Invar
- Size
- 900 × 600 × 3 mm
- Key callouts
- Slot pattern ±0.10 mm, hole-to-edge 6 mm
- Batch
- 150 pcs
Cut with common-line pairs to halve the pierce count.
Bracket blank
- Material
- Invar
- Size
- 250 × 120 × 4 mm
- Key callouts
- Contour ±0.10 mm, bend-relief notches
- Batch
- 800 pcs
Bend reliefs cut in at the same time so the press brake does not tear the corner.
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 Plasma 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 Plasma 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
What material thickness or size range suits CNC Plasma Cutting Invar?
Laser-cut Invar thickness depends on the alloy and its reflectivity; we tune the fiber source and assist gas accordingly.
Which industries use CNC Plasma Cutting Invar parts?
CNC Plasma Cutting Invar parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise Invar components are required.
Does CNC Plasma Cutting Invar require dedicated tooling?
Most Invar cutting work uses standard cutting tools and CNC programs; dedicated fixtures are made only when geometry or volume requires them.
How clean are the edges produced by CNC Plasma Cutting on Invar?
Laser cutting leaves Invar with a narrow kerf and a clean, near burr-free edge and only a small heat-affected zone.