CNC Centerless Grinding Kovar is a core capability at VT machining. We combine controlled grinding with material-aware setup for Kovar — an alloy that is matched thermal expansion for glass/ceramic seals — to produce parts that meet your specification first time.
CNC Centerless Grinding Capability for Kovar
- No center holes needed
- High throughput
- Diameter ±0.003 mm
- Through-feed & in-feed
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 Centerless Grinding Kovar Works
An abrasive wheel removes a fine, controlled layer from the Kovar part. Wheel specification, dressing interval, infeed and coolant are matched to the alloy's hardness so the surface is not burned or left with residual stress.
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 Centerless Grinding Kovar
| Feature | Standard | Precision |
|---|---|---|
| Size (OD, ID, thickness) | ±0.005 mm | ±0.002 mm |
| Flatness over 100 mm | 0.010 mm | 0.003 mm |
| Parallelism | 0.010 mm | 0.003 mm |
| Roundness | 0.005 mm | 0.002 mm |
| Squareness | 0.010 mm | 0.005 mm |
| Surface finish | Ra 0.4 µm | Ra 0.1 µm |
| Workpiece hardness | up to 62 HRC | up to 65 HRC |
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 Centerless Grinding Tolerances & Surface Finish
Ground Kovar reaches single-micron tolerances on size, flatness and parallelism, with surface finishes down to Ra 0.1–0.4 µm — and a near-mirror finish on suitable alloys.
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.
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 Centerless Grinding 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.
Design Tips for CNC Centerless Grinding Kovar
We are happy to suggest design tweaks that improve manufacturability. Allowing adequate grind stock, specifying realistic flatness over the true datum, and relieving corners help us hit tight tolerances on Kovar efficiently. If you send your model early, we will return practical DFM feedback before you commit to production.
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.
Applications of CNC Centerless Grinding Kovar
Customers order CNC Centerless Grinding 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 Centerless Grinding 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 Centerless Grinding 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.
Gauge block set
- Material
- Kovar
- Size
- 50 × 30 × 10 mm
- Key callouts
- Thickness ±0.002 mm, flatness 0.002 mm, parallelism 0.002 mm
- Batch
- 200 pcs
Ground wet in one chucking, then left to normalise before final inspection at 20 °C.
Slitter blade
- Material
- Kovar
- Size
- Ø150 × 1.5 mm
- Key callouts
- Thickness ±0.005 mm, edge concentricity 0.005 mm
- Batch
- 400 pcs
Ground in a stack so all blades in a set share the same thickness.
Lapping plate
- Material
- Kovar
- Size
- 300 × 300 × 30 mm
- Key callouts
- Flatness 0.005 mm over the full face
- Batch
- 20 pcs
Ground, stress-relieved, ground again — one pass will not hold flatness on this area.
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 Centerless Grinding 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 Centerless Grinding
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
Can VT machining make custom Kovar parts to my drawing?
Yes. Kovar Kovar grinding is made to order from your CAD/2D drawing. Share your geometry, material grade, tolerance and quantity and we will confirm feasibility, lead time and pricing.
Which industries use CNC Centerless Grinding Kovar parts?
CNC Centerless Grinding Kovar parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise Kovar components are required.
How clean are the edges produced by CNC Centerless Grinding on Kovar?
Machined Kovar edges are clean and to specification; edge-break or deburring is added when your drawing calls for it.
Does CNC Centerless Grinding Kovar require dedicated tooling?
Most Kovar grinding work uses standard cutting tools and CNC programs; dedicated fixtures are made only when geometry or volume requires them.
Why is Kovar a good choice for CNC Centerless Grinding?
Kovar is matched thermal expansion for glass/ceramic seals, which makes it well suited to CNC Centerless Grinding. We tune the process to the alloy so the finished Kovar grinding part meets your dimensional and functional requirements.