CNC Sinker EDM Brass from VT machining delivers precision Brass parts produced to your exact drawing. Sinker (die-sink) EDM burns a shaped electrode into metal to form precise cavities and blind features, and we tune every parameter to the behaviour of Brass, which is free-machining, good conductivity, attractive finish.
Process Data for CNC Sinker EDM Brass
| Electrode | Graphite (roughing) / copper (fine finish) |
|---|---|
| Relative removal rate | High (vs tool steel = medium) |
| Best finish | VDI 12-18 (Ra 0.4-0.8 µm) |
Shown for C360 Brass, the most common Brass grade we see for CNC Sinker EDM. Typical values for C360 Brass, Half-hard; confirmed on the first part.
CNC Sinker EDM Capability for Brass
- Blind cavities & ribs
- Fine surface (VDI grades)
- Tolerance to ±0.005 mm
- Hardened tool steel
Brass material properties, finishing options and grade notes are on our CNC Wire EDM Brass page.
How CNC Sinker EDM Brass Works
Material is removed from the Brass workpiece by controlled electrical discharges across a dielectric gap, with no mechanical contact. Flushing, on/off pulse timing and electrode/wire feed are set to balance speed against surface finish.
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 Sinker EDM Brass
| Feature | Standard | Precision |
|---|---|---|
| Profile dimension | ±0.010 mm | ±0.002 mm |
| Internal corner radius | 0.15 mm | 0.05 mm |
| Taper control over 50 mm | 0.02 mm | 0.005 mm |
| Surface finish (skim passes) | Ra 0.8 µm | Ra 0.2 µm |
| Recast layer | 10 µm | 2 µm (fine skim) |
| Start-hole diameter | 1.0 mm | 0.25 mm |
| Workpiece hardness | no limit (conductive) | no limit (conductive) |
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 Sinker EDM Tolerances & Surface Finish
EDM holds tolerances to roughly ±0.002–0.005 mm with no cutting force on the Brass part, producing fine, controlled surface textures and sharp internal corners impossible to mill.
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 Sinker EDM Brass
A few design choices make a real difference to cost and quality. EDM suits sharp internal corners, thin ribs and hardened Brass that cannot be milled; allowing a small corner radius where possible speeds the cut. If you send your model early, we will return practical DFM feedback before you commit to production.
Applications of CNC Sinker EDM Brass
CNC Sinker EDM of Brass 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 Brass Parts for CNC Sinker EDM
Illustrative examples of CNC Sinker EDM 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.
Spline broach section
- Material
- Brass
- Size
- Ø28 × 40 mm
- Key callouts
- Involute profile ±0.005 mm, Ra 0.4 µm
- Batch
- 60 pcs
Wire EDM after hardening to 62 HRC — the profile would not survive being cut soft and heat-treated.
Injection mould cavity rib
- Material
- Brass
- Size
- 0.25 mm wide × 8 mm deep
- Key callouts
- Width ±0.005 mm, VDI 21 finish
- Batch
- 45 pcs
Sinker EDM with a graphite electrode; a cutter that thin would break in the first pass.
Turbine blade fir-tree root
- Material
- Brass
- Size
- 40 × 25 mm section
- Key callouts
- Profile ±0.008 mm
- Batch
- 120 pcs
Held on a dedicated fixture so every blade in the set indexes identically.
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 Sinker EDM 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 Sinker EDM
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
What tolerances can you hold for CNC Sinker EDM Brass?
Achievable tolerances for Brass EDM machining depend on the alloy, geometry and feature size. EDM holds tolerances to around ±0.002 mm with no cutting force on the part. Exact figures are confirmed against your drawing callouts.
What surface finish is achievable on Brass with CNC Sinker EDM?
Surface finish on Brass is controlled to your specification; we confirm the achievable Ra against your callout.
What material thickness or size range suits CNC Sinker EDM Brass?
We machine Brass across a broad size range; share your part envelope for confirmation.
Which industries use CNC Sinker EDM Brass parts?
CNC Sinker EDM Brass parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise Brass components are required.
Can VT machining make custom Brass parts to my drawing?
Yes. Brass EDM machining 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.
What is the typical lead time and minimum order for CNC Sinker EDM Brass?
CNC Sinker EDM prototypes for Brass can be produced quickly and scaled to series production. Send your drawing and quantity and we will advise lead time and any minimum order.