Looking for reliable CNC Boring Brass? VT machining manufactures Brass parts to tight tolerances and consistent quality. Brass is free-machining, good conductivity, attractive finish, so the process is set up specifically for the material.
Starting Parameters for CNC Boring Brass
| Cutting speed (carbide) | 270-545 m/min |
|---|---|
| Feed | 0.07-0.245 mm/rev |
| Spindle speed, Ø30 mm bore | 2860-5780 rpm |
| Insert / tool class | ISO N — sharp, polished, uncoated or DLC |
| Coolant | Dry or light emulsion; zero-rake tools to prevent grabbing |
Shown for C360 Brass, the most common Brass grade we see for CNC Boring. Starting values for C360 Brass, Half-hard; optimised on the first article.
CNC Boring Capability for Brass
- Bore tolerance to IT6
- Roundness within 0.005 mm
- Fine boring heads
- Large-diameter capability
Brass material properties, finishing options and grade notes are on our CNC Turning Brass page.
How CNC Boring Brass Works
The Brass bar or billet rotates in the spindle while single-point tools shape outer diameters, bores, faces, grooves and threads. Constant surface speed control keeps cutting conditions stable from large to small diameters.
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 Boring Brass
| Feature | Standard | Precision |
|---|---|---|
| Outside diameter | ±0.05 mm | ±0.005 mm |
| Bore diameter | H9 | H6 |
| Length / shoulder position | ±0.10 mm | ±0.020 mm |
| Concentricity OD to ID | 0.05 mm TIR | 0.010 mm TIR |
| Roundness | 0.02 mm | 0.005 mm |
| Thread class | 6g / 2A | 4h / 3A |
| Surface finish, as turned | 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.
CNC Boring Tolerances & Surface Finish
Turned Brass holds diameter tolerances to about ±0.005 mm with concentricity within 0.01 mm and good roundness. Turned finishes of Ra 0.4–0.8 µm are achievable with finishing passes and sharp tooling.
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 Boring Brass
We are happy to suggest design tweaks that improve manufacturability. Consistent diameters, standard thread forms and avoiding extremely long, slender features help Brass turned parts stay concentric and economical. If you send your model early, we will return practical DFM feedback before you commit to production.
Applications of CNC Boring Brass
Customers order CNC Boring Brass 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.
Typical Brass Parts for CNC Boring
Illustrative examples of CNC Boring Brass 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.
Nozzle body
- Material
- Brass
- Size
- Ø12 × 46 mm
- Key callouts
- Ø0.6 mm orifice ±0.01 mm, internal taper 20°
- Batch
- 600 pcs
Orifice EDM-drilled after turning; a drill wanders at that diameter.
Bearing spacer
- Material
- Brass
- Size
- Ø35 / Ø22 × 9 mm
- Key callouts
- Thickness ±0.005 mm, parallelism 0.005 mm
- Batch
- 4,000 pcs
Turned then double-disc ground — thickness this tight is not a lathe job.
Valve seat
- Material
- Brass
- Size
- Ø28 × 14 mm
- Key callouts
- Seat angle 45° ±0.1°, roundness 0.005 mm, Ra 0.2 µm
- Batch
- 800 pcs
Seat finished with a single-point diamond pass, no interruption.
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 Boring Brass
- 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 Brass 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 Boring
Other Processes for Brass
Send the drawing, the Brass 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 Brass parts to my drawing?
Yes. Brass turning 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.
Does CNC Boring Brass require dedicated tooling?
Most Brass turning work uses standard cutting tools and CNC programs; dedicated fixtures are made only when geometry or volume requires them.
What tolerances can you hold for CNC Boring Brass?
Achievable tolerances for Brass turning depend on the alloy, geometry and feature size. Turning holds diameter tolerances to around ±0.005 mm with concentricity within 0.01 mm. Exact figures are confirmed against your drawing callouts.
What surface finish is achievable on Brass with CNC Boring?
Surface finish on Brass is controlled to your specification; we confirm the achievable Ra against your callout.
What is CNC Boring Brass and how is it done?
CNC Boring Brass refers to boring enlarges and finishes existing holes to precise diameter, roundness and surface finish. Applied to Brass — free-machining, good conductivity, attractive finish — VT machining produces each part to your CAD drawing, selecting parameters from your tolerance, finish and quantity requirements.