Chemical Etching Invar is a core capability at VT machining. We combine controlled etching with material-aware setup for Invar — an alloy that is ultra-low expansion; etched for masks and precision frames — to produce parts that meet your specification first time.
Chemical Etching Capability for Invar
- Foil thickness 0.02–1.0 mm
- Minimum feature ≈ 0.8 × metal thickness
- Burr-free, stress-free edges
- Tooling-free: revise artwork digitally
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 Chemical Etching Invar Works
A photo-resist patterned from your artwork masks the Invar, and an etchant dissolves the exposed metal evenly from both sides. Because there is no mechanical force, the part stays flat and stress-free.
Every job begins from your CAD model or 2D drawing. Fixturing and tool paths are planned so the most critical dimensions are produced in the most rigid, repeatable setup. Critical dimensions are checked on the first part and monitored through the run.
Achievable Tolerances for Chemical Etching Invar
| Feature | Standard | Precision |
|---|---|---|
| Feature dimension | ±0.05 mm | ±0.02 mm |
| Minimum feature width | 1.0 × thickness | 0.8 × thickness |
| Foil thickness range | 0.02–1.0 mm | 0.05–0.5 mm |
| Edge condition | burr-free | burr-free, no HAZ |
| Flatness of etched part | 0.1 mm over 100 mm | 0.05 mm over 100 mm |
| Half-etch depth control | ±20% of depth | ±10% of depth |
| Tab / breakout size | 0.5 mm | 0.3 mm |
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 offers a useful combination of properties: it is ultra-low expansion; etched for masks and precision frames. Those characteristics shape how we approach chemical etching — from tool and parameter selection to work-holding and coolant.
If your application is sensitive to alloy condition, we agree the specification in writing and document it. Stock is sourced from reputable suppliers so what you order is what you receive.
Chemical Etching Quality & Inspection
Consistent quality comes from disciplined process control. Critical dimensions on Invar parts are checked in-process and verified at final inspection using calibrated instruments and, where required, CMM measurement. Full documentation — dimensional reports, mill certs, FAIR — is available when your programme needs it.
Design Tips for Chemical Etching Invar
A few design choices make a real difference to cost and quality. Designing features no finer than ~0.8× foil thickness and allowing tab placement gives the best yield on etched Invar. If you send your model early, we will return practical DFM feedback before you commit to production.
Chemical Etching Tolerances & Surface Finish
Etched Invar holds tight, repeatable feature tolerances on thin gauge, with a minimum feature size around 0.8× the metal thickness and completely burr-free edges.
Final tolerances are governed by the material's behaviour, wall thickness and overall stiffness. We give honest DFM feedback if a callout would be costly or better achieved another way.
Secondary Operations & Finishing
We complete Invar components with the secondary steps your drawing calls for. We arrange heat treatment, surface treatment, marking and assembly as needed. Tell us the final spec and we will plan the full route so parts arrive ready to use.
Applications of Chemical Etching Invar
Chemical Etching of Invar supports parts across aerospace, medical, automotive, electronics, semiconductor, energy and general industrial sectors. We scale from one-off prototypes to ongoing production while holding the same quality.
How to Order Chemical Etching Invar
Ordering Invar parts is straightforward. Provide the drawing, material, quantity and any certification needs. Our engineers reply — in English — with feasibility, pricing and a realistic lead time, usually within one business day.
Parts We Have Run in Invar
Three representative Chemical Etching 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.
Filter screen
- Material
- Invar
- Size
- Ø25 × 0.08 mm
- Key callouts
- 0.06 mm holes, 40% open area
- Batch
- 15,000 pcs
Minimum feature is about 0.8 × thickness, which sets the smallest hole worth quoting.
Lead frame
- Material
- Invar
- Size
- 60 × 30 × 0.15 mm
- Key callouts
- Track width 0.15 ±0.02 mm, burr-free
- Batch
- 40,000 pcs
No mechanical force means no distortion — the frame is flat straight out of the etch line.
EMI shielding mesh
- Material
- Invar
- Size
- 120 × 80 × 0.1 mm
- Key callouts
- Aperture 0.20 ±0.02 mm, 55% open area
- Batch
- 8,000 pcs
Etched from both sides at once so the aperture wall stays symmetrical.
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 Chemical Etching 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 Chemical Etching
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 Chemical Etching Invar?
Because chemical etching needs no hard tooling, Invar etching prototypes turn around quickly and scale to volume from the same digital artwork. Send your drawing and quantity for an exact lead time and MOQ.
Why is Invar a good choice for Chemical Etching?
Invar is ultra-low expansion; etched for masks and precision frames, which makes it well suited to Chemical Etching. We tune the process to the alloy so the finished Invar etching part meets your dimensional and functional requirements.
What material thickness or size range suits Chemical Etching Invar?
Etching suits Invar foil roughly 0.02–1.0 mm thick — the thinner the foil, the finer the achievable detail.
Which industries use Chemical Etching Invar parts?
Chemical Etching Invar parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise Invar components are required.
What surface finish is achievable on Invar with Chemical Etching?
Etching leaves Invar with a uniform matte surface and clean, burr-free edges, with optional post-etch finishing.
Does Chemical Etching Invar require dedicated tooling?
No. Invar etching is tooling-free — the pattern is a photo-resist made from your artwork, so design changes cost nothing in tooling and prototypes are fast.