CNC Honing Invar is a core capability at VT machining. We combine controlled finishing with material-aware setup for Invar — an alloy that is ultra-low thermal expansion — to produce parts that meet your specification first time.
Process Data for CNC Honing Invar
| Stone | Aluminium oxide or CBN |
|---|---|
| Size tolerance | Ø ±0.002-0.005 mm, roundness ≤0.002 mm |
| Surface finish | Ra 0.1-0.3 µm, 30-45° cross-hatch |
Shown for Invar 36, the most common Invar grade we see for CNC Honing. Typical values for Invar 36, Annealed; confirmed on the first part.
CNC Honing Capability for Invar
- Bore Ra to 0.1 µm
- Cross-hatch pattern
- Roundness within 0.002 mm
- Hydraulic-bore finishing
Invar material properties, finishing options and grade notes are on our CNC Polishing Invar page.
How CNC Honing Invar Works
Abrasive media or tooling refine the Invar surface in controlled stages, removing the previous step's marks until the target roughness and edge condition are reached.
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 Honing Invar
| Feature | Standard | Precision |
|---|---|---|
| Surface roughness | Ra 0.8 µm | Ra 0.05 µm |
| Edge break | 0.1–0.3 mm | 0.05 ±0.02 mm |
| Material removed | 0.02 mm | 0.005 mm |
| Bore roundness after honing | 0.005 mm | 0.002 mm |
| Cross-hatch angle | 45° ±10° | 45° ±5° |
| Cosmetic grade | uniform satin | mirror, no visible lines |
| Masking of datum faces | on request | standard |
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 Honing Tolerances & Surface Finish
Finishing brings Invar to a defined roughness target — from a uniform satin to Ra values as low as 0.05 µm — with controlled, repeatable edge breaks.
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.
Design Tips for CNC Honing Invar
A few design choices make a real difference to cost and quality. Telling us the target Ra, the cosmetic faces and any masking needs lets us finish Invar efficiently without over-processing. If you send your model early, we will return practical DFM feedback before you commit to production.
Applications of CNC Honing Invar
CNC Honing of Invar 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 Invar Parts for CNC Honing
Illustrative examples of CNC Honing Invar 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.
Mirror-polished insert
- Material
- Invar
- Size
- 80 × 50 mm cavity
- Key callouts
- Ra 0.05 µm, SPI A2
- Batch
- 60 pcs
Polished in five abrasive stages; skipping one leaves scratches the next cannot remove.
Sealing face
- Material
- Invar
- Size
- Ø60 mm face
- Key callouts
- Ra 0.2 µm, flatness 0.005 mm
- Batch
- 1,000 pcs
Lapped after grinding; the seal spec is a roughness number, not a dimension.
Hydraulic bore
- Material
- Invar
- Size
- Ø32 × 200 mm
- Key callouts
- Ra 0.4 µm cross-hatch 45°, roundness 0.003 mm
- Batch
- 600 pcs
Honed in three stages; the cross-hatch is what holds the oil film.
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 Honing Invar
- 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 Invar 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 Honing
Other Processes for Invar
Send the drawing, the Invar 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 is the typical lead time and minimum order for CNC Honing Invar?
CNC Honing prototypes for Invar 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 surface finish is achievable on Invar with CNC Honing?
Our finishing processes refine Invar surfaces to Ra values as low as 0.05 µm for cosmetic or sealing faces.
Why is Invar a good choice for CNC Honing?
Invar is ultra-low thermal expansion, which makes it well suited to CNC Honing. We tune the process to the alloy so the finished Invar finishing part meets your dimensional and functional requirements.
What is CNC Honing Invar and how is it done?
CNC Honing Invar refers to honing finishes bores with abrasive stones to precise size, roundness and a cross-hatch surface. Applied to Invar — ultra-low thermal expansion — VT machining produces each part to your CAD drawing, selecting parameters from your tolerance, finish and quantity requirements.
How clean are the edges produced by CNC Honing on Invar?
Our deburring leaves Invar with a consistent, controlled edge break and burr-free surfaces.
Does CNC Honing Invar require dedicated tooling?
Most Invar finishing work uses standard cutting tools and CNC programs; dedicated fixtures are made only when geometry or volume requires them.