VT machining provides CNC Grinding Kovar for customers who need accurate, repeatable Kovar components. Because Kovar is matched thermal expansion for glass/ceramic seals, we adapt the process to suit — controlling the variables that matter for this alloy.
Process Data for CNC Grinding Kovar
| Wheel (supply condition) | Aluminium oxide, soft grade |
|---|---|
| Depth per pass (rough / finish) | 0.01-0.03 / 0.002-0.005 mm |
| Achievable finish | Ra 0.2-0.4 µm |
| Typical size tolerance | Ø ±0.002 mm, roundness 0.001-0.002 mm |
| Thermal growth, 200 mm part, +2 °C | 2 µm (CTE 5.1 µm/m·K) |
Shown for Kovar, the most common Kovar grade we see for CNC Grinding. Typical values for Kovar, Annealed; confirmed on the first part.
CNC Grinding Capability for Kovar
- Surface finish to Ra 0.1–0.4 µm
- Dimensional tolerance to ±0.002 mm
- Flatness/parallelism within 0.005 mm
- Wheel grit selected per alloy hardness
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 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.
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 CNC 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 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.
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.
Working with Kovar
Kovar offers a useful combination of properties: it is matched thermal expansion for glass/ceramic seals. Those characteristics shape how we approach grinding — 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.
Design Tips for CNC Grinding Kovar
A few design choices make a real difference to cost and quality. 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 Grinding Kovar
CNC Grinding of Kovar 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.
Typical Kovar Parts for CNC Grinding
Illustrative examples of CNC Grinding Kovar parts and the callouts that usually drive the process plan. They show the kind of work that fits this process; they are not specific customer orders.
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.
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.
Punch tool
- Material
- Kovar
- Size
- Ø10 × 60 mm
- Key callouts
- OD ±0.002 mm, roundness 0.002 mm, Ra 0.1 µm
- Batch
- 300 pcs
Cylindrical ground after hardening to 60 HRC — machining soft would not hold the size.
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 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 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 Grinding on Kovar?
Machined Kovar edges are clean and to specification; edge-break or deburring is added when your drawing calls for it.
What is the typical lead time and minimum order for CNC Grinding Kovar?
CNC Grinding 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.
What is CNC Grinding Kovar and how is it done?
CNC Grinding Kovar refers to cNC grinding removes material with a precision abrasive wheel to achieve tight dimensional tolerances and superior surface finish. Applied to Kovar — matched thermal expansion for glass/ceramic seals — VT machining produces each part to your CAD drawing, selecting parameters from your tolerance, finish and quantity requirements.
Which industries use CNC Grinding Kovar parts?
CNC Grinding Kovar parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise Kovar components are required.
What surface finish is achievable on Kovar with CNC Grinding?
Grinding can take Kovar to a fine finish — typically Ra 0.1–0.4 µm, and to a mirror grade on suitable alloys.
Does CNC 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.