CNC Cylindrical Grinding Kovar from VT machining delivers precision Kovar parts produced to your exact drawing. Cylindrical grinding finishes outer diameters of rotational parts to precise size and roundness, and we tune every parameter to the behaviour of Kovar, which is matched thermal expansion for glass/ceramic seals.
CNC Cylindrical Grinding Capability for Kovar
- Roundness within 0.002 mm
- OD tolerance ±0.002 mm
- Ra to 0.2 µm
- Between-centers work
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 Cylindrical 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.
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 Cylindrical 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.
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.
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.
CNC Cylindrical Grinding 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.
CNC Cylindrical 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.
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.
Design Tips for CNC Cylindrical Grinding Kovar
Small design adjustments often cut cost and lead time. 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.
Applications of CNC Cylindrical Grinding 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 Cylindrical Grinding 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 Cylindrical 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 Cylindrical 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 Cylindrical 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
How clean are the edges produced by CNC Cylindrical Grinding on Kovar?
Machined Kovar edges are clean and to specification; edge-break or deburring is added when your drawing calls for it.
Why is Kovar a good choice for CNC Cylindrical Grinding?
Kovar is matched thermal expansion for glass/ceramic seals, which makes it well suited to CNC Cylindrical Grinding. We tune the process to the alloy so the finished Kovar grinding part meets your dimensional and functional requirements.
What tolerances can you hold for CNC Cylindrical Grinding Kovar?
Achievable tolerances for Kovar grinding depend on the alloy, geometry and feature size. Grinding routinely holds single-micron tolerances on diameter, flatness and parallelism. Exact figures are confirmed against your drawing callouts.
Which industries use CNC Cylindrical Grinding Kovar parts?
CNC Cylindrical Grinding Kovar parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise Kovar components are required.