Looking for reliable CNC Wire EDM Kovar? VT machining manufactures Kovar parts to tight tolerances and consistent quality. Kovar is matched thermal expansion for glass/ceramic seals, so the process is set up specifically for the material.
CNC Wire EDM Capability for Kovar
- Kerf from 0.1 mm
- Tolerance to ±0.002 mm
- Hardened & exotic alloys
- Sharp internal corners
Kovar Material Data
| Density | 8.36 g/cm³ |
|---|---|
| Tensile strength | 517 MPa |
| Yield strength (0.2%) | 340 MPa |
| Hardness | 140–160 HV |
| Melting point | 1450 °C |
| Thermal conductivity | 17.3 W/m·K |
| Thermal expansion | 5.1 (30–200 °C) ×10⁻⁶/K |
| Electrical conductivity | 3.5% |
| Machinability (C36000 = 100%) | 35% |
| Grades we run | Kovar / ASTM F15, Alloy 42, Alloy 52 |
Published typical values for Kovar (ASTM F15). Other grades in the family differ — the certificate supplied with your order carries the actual heat-lot figures.
Sealing surfaces must stay clean. Parts destined for glass-to-metal seals are degreased and handled without bare hands after final machining.
How CNC Wire EDM Kovar Works
Material is removed from the Kovar workpiece by controlled electrical discharges across a dielectric gap, with no mechanical contact. Flushing, on/off pulse timing and electrode/wire feed are set to balance speed against surface finish.
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 Wire EDM Kovar
| Feature | Standard | Precision |
|---|---|---|
| Profile dimension | ±0.010 mm | ±0.002 mm |
| Internal corner radius | 0.15 mm | 0.05 mm |
| Taper control over 50 mm | 0.02 mm | 0.005 mm |
| Surface finish (skim passes) | Ra 0.8 µm | Ra 0.2 µm |
| Recast layer | 10 µm | 2 µm (fine skim) |
| Start-hole diameter | 1.0 mm | 0.25 mm |
| Workpiece hardness | no limit (conductive) | no limit (conductive) |
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 Wire EDM 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 Wire EDM Kovar
Small design adjustments often cut cost and lead time. EDM suits sharp internal corners, thin ribs and hardened Kovar that cannot be milled; allowing a small corner radius where possible speeds the cut. If you send your model early, we will return practical DFM feedback before you commit to production.
CNC Wire EDM Tolerances & Surface Finish
EDM holds tolerances to roughly ±0.002–0.005 mm with no cutting force on the Kovar part, producing fine, controlled surface textures and sharp internal corners impossible to mill.
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 Kovar 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.
Working with Kovar
Kovar is matched thermal expansion for glass/ceramic seals. 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.
Applications of CNC Wire EDM Kovar
Kovar 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 Wire EDM Kovar
Starting your project takes one email. Send your CAD or 2D drawing, the Kovar 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 Kovar
Three representative CNC Wire EDM Kovar 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.
Turbine blade fir-tree root
- Material
- Kovar
- Size
- 40 × 25 mm section
- Key callouts
- Profile ±0.008 mm
- Batch
- 120 pcs
Held on a dedicated fixture so every blade in the set indexes identically.
Extrusion die
- Material
- Kovar
- Size
- 120 × 120 × 25 mm
- Key callouts
- Profile ±0.005 mm, internal corner R0.1 mm
- Batch
- 35 pcs
Cut in four skim passes; the first pass is speed, the last three are finish and accuracy.
Spline broach section
- Material
- Kovar
- Size
- Ø28 × 40 mm
- Key callouts
- Involute profile ±0.005 mm, Ra 0.4 µm
- Batch
- 60 pcs
Wire EDM after hardening to 62 HRC — the profile would not survive being cut soft and heat-treated.
Finishing Options for Kovar
| 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 Wire EDM Kovar
- 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 Kovar 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 Wire EDM
Other Processes for Kovar
Send the drawing, the Kovar grade and the quantity. You get pricing, lead time and any DFM notes back — usually within one business day.
Request a QuoteFrequently Asked Questions
Why is Kovar a good choice for CNC Wire EDM?
Kovar is matched thermal expansion for glass/ceramic seals, which makes it well suited to CNC Wire EDM. We tune the process to the alloy so the finished Kovar EDM machining part meets your dimensional and functional requirements.
What material thickness or size range suits CNC Wire EDM Kovar?
We machine Kovar across a broad size range; share your part envelope for confirmation.
Does CNC Wire EDM Kovar require dedicated tooling?
Wire EDM needs no shaped tooling; sinker EDM uses a shaped electrode we produce in-house for your cavity.
What is the typical lead time and minimum order for CNC Wire EDM Kovar?
CNC Wire EDM prototypes for Kovar can be produced quickly and scaled to series production. Send your drawing and quantity and we will advise lead time and any minimum order.