CNC Broaching Kovar from VT machining delivers precision Kovar parts produced to your exact drawing. Broaching pushes a toothed tool through or across a part to form keyways, splines and internal profiles, and we tune every parameter to the behaviour of Kovar, which is matched thermal expansion for glass/ceramic seals.
CNC Broaching Capability for Kovar
- Keyways & splines
- Internal profiles
- One-pass forming
- High repeatability
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 Broaching Kovar Works
Rotating multi-flute cutters remove material as the Kovar 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.
Programming is driven directly by your 3D model or print. Work-holding, tool selection and the cutting strategy are planned around the critical features and the material before the first chip is cut. First-off inspection confirms the process is centred before production continues.
Achievable Tolerances for CNC Broaching Kovar
| 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.
Secondary Operations & Finishing
Finished Kovar parts can move straight into secondary operations under one roof. Typical add-ons are deburring, passivation, anodising, plating, blasting, polishing and laser marking. We coordinate the whole chain so you receive complete, inspection-ready parts.
Working with Kovar
As a material, Kovar is matched thermal expansion for glass/ceramic seals. Our setup reflects the alloy's machinability so the finished part is accurate and free of avoidable defects.
We verify the exact grade and condition before machining, and traceable mill certs are available on request. We can work to your nominated material source or specification when required.
CNC Broaching Quality & Inspection
We control quality throughout the process, not just at the end. In-process checks plus final inspection — including CMM where specified — keep every Kovar part to print. Inspection reports, material certificates and first-article documentation can be supplied on request.
CNC Broaching Tolerances & Surface Finish
For CNC Broaching, 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.
Exact achievable figures depend on the alloy, the feature size and the part geometry. Tell us which dimensions are critical and we will advise feasibility up front.
Design Tips for CNC Broaching Kovar
We are happy to suggest design tweaks that improve manufacturability. Generous internal radii, sensible pocket depth-to-width ratios and avoiding very thin unsupported walls all reduce cost and improve accuracy in Kovar. If you send your model early, we will return practical DFM feedback before you commit to production.
Applications of CNC Broaching Kovar
Customers order CNC Broaching Kovar components for everything from instrumentation to structural and functional assemblies. Whether you need a single prototype or recurring production volume, the same process discipline applies.
How to Order CNC Broaching Kovar
Getting a quote is simple. Share your model, the material grade, your quantity and target tolerances. You receive a clear quotation with lead time and honest manufacturability feedback.
Parts We Have Run in Kovar
Three representative CNC Broaching 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.
Optical mount plate
- Material
- Kovar
- 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.
Vacuum chamber flange
- Material
- Kovar
- Size
- Ø180 × 20 mm
- Key callouts
- Knife-edge seal Ra 0.4 µm, bolt circle ±0.05 mm
- Batch
- 60 pcs
Sealing face finished last, then handled in gloves and bagged straight off the machine.
Robot end-effector bracket
- Material
- Kovar
- 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.
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 Broaching 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 Broaching
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
What tolerances can you hold for CNC Broaching Kovar?
Achievable tolerances for Kovar 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.
Which industries use CNC Broaching Kovar parts?
CNC Broaching Kovar parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise Kovar components are required.
Why is Kovar a good choice for CNC Broaching?
Kovar is matched thermal expansion for glass/ceramic seals, which makes it well suited to CNC Broaching. We tune the process to the alloy so the finished Kovar machining part meets your dimensional and functional requirements.
What material thickness or size range suits CNC Broaching Kovar?
We machine Kovar across a broad size range; share your part envelope for confirmation.
How clean are the edges produced by CNC Broaching on Kovar?
Machined Kovar edges are clean and to specification; edge-break or deburring is added when your drawing calls for it.