CNC EDM Drilling 309S Stainless Steel from VT machining delivers precision 309S Stainless Steel parts made to your exact drawing. Fast-hole EDM drilling produces small, deep holes in hard metals, including starter holes for wire EDM, with parameters tuned to 309S Stainless Steel, which is corrosion resistant, strong and hygienic.
CNC EDM Drilling Capability for 309S Stainless Steel
- Austenitic/martensitic grades
- Corrosion resistant
- Tolerance to ±0.01 mm
- Typical hardness 70–200 HB (annealed)
309S Stainless Steel Material Data
| Density | 8.00 g/cm³ |
|---|---|
| Tensile strength | 515 MPa |
| Yield strength (0.2%) | 205 MPa |
| Hardness | 170 HB |
| Melting point | 1400–1450 °C |
| Thermal conductivity | 16.2 W/m·K |
| Thermal expansion | 17.3 ×10⁻⁶/K |
| Electrical conductivity | 2.4% |
| Machinability (C36000 = 100%) | 45% |
| Grades we run | 303, 304/304L, 316/316L, 321, 410, 416, 420, 17-4PH, 2205 duplex |
Published typical values for 304. Other grades in the family differ — the certificate supplied with your order carries the actual heat-lot figures.
It work-hardens the moment a tool dwells. Constant feed and positive-rake tooling; a rubbing pass leaves a glazed skin the next tool cannot get through.
Machining 309S Stainless Steel with CNC EDM Drilling
309S Stainless Steel behaves predictably under CNC EDM Drilling once parameters are dialled in: machinability is moderate; work-hardens, so positive-rake tooling and steady feeds are used to avoid glazing, and we tune the operation accordingly.
We hold reference parameters for this grade, so repeat orders of 309S Stainless Steel run consistently from one batch to the next.
Achievable Tolerances for CNC EDM Drilling 309S Stainless Steel
| 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 EDM Drilling Tolerances & Surface Finish
EDM holds tolerances to roughly ±0.002–0.005 mm with no cutting force on the 309S Stainless Steel 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 EDM Drilling 309S Stainless Steel
We are happy to suggest design tweaks that improve manufacturability. EDM suits sharp internal corners, thin ribs and hardened 309S Stainless Steel 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.
Why 309S Stainless Steel?
309S Stainless Steel is chosen when a part needs what this grade offers — it is corrosion resistant, strong and hygienic. We confirm the grade and any temper or heat-treat condition with you before machining.
Secondary Operations & Finishing
Finished 309S Stainless Steel parts can move straight into secondary operations under one roof. Typical add-ons are deburring, passivation, anodising, plating, blasting, polishing and laser marking. We coordinate the whole chain so you receive complete, inspection-ready parts.
CNC EDM Drilling Quality & Inspection
We control quality throughout the process, not just at the end. In-process checks plus final inspection — including CMM where specified — keep every 309S Stainless Steel part to print. Inspection reports, material certificates and first-article documentation can be supplied on request.
Applications of CNC EDM Drilling 309S Stainless Steel
Customers order CNC EDM Drilling 309S Stainless Steel 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.
How to Order CNC EDM Drilling 309S Stainless Steel
Getting a quote is simple. Share your model, the material grade, your quantity and target tolerances. You receive a clear quotation with lead time and honest manufacturability feedback.
Finishing Options for 309S Stainless Steel
| Finish | Thickness / effect | Why it gets specified |
|---|---|---|
| Citric passivation | — | ASTM A967 / AMS 2700, removes free iron |
| Electropolish | 5–25 µm removed | Ra improves by roughly half, hygienic surface |
| Brushed / grained | Ra 0.4–1.6 µm | No. 4 finish, directional |
| PVD coating | 2–5 µm | TiN, TiCN for wear surfaces |
| 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 EDM Drilling 309S Stainless Steel
- 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 309S Stainless Steel 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.
309S Stainless Steel in Other Processes
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Send the drawing, the 309S Stainless Steel condition and the quantity — pricing and lead time come back the same or next business day.
Request a QuoteFrequently Asked Questions
How clean are the edges produced by CNC EDM Drilling on 309S Stainless Steel?
Machined 309S Stainless Steel edges are clean and to specification; edge-break or deburring is added when your drawing calls for it.
What tolerances can you hold for CNC EDM Drilling 309S Stainless Steel?
Achievable tolerances for 309S Stainless Steel 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.
Which industries use CNC EDM Drilling 309S Stainless Steel parts?
CNC EDM Drilling 309S Stainless Steel parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise 309S Stainless Steel components are required.
What is the typical lead time and minimum order for CNC EDM Drilling 309S Stainless Steel?
CNC EDM Drilling prototypes for 309S Stainless Steel can be produced quickly and scaled to series production. Send your drawing and quantity and we will advise lead time and any minimum order.
Why is 309S Stainless Steel a good choice for CNC EDM Drilling?
309S Stainless Steel is corrosion resistant, strong and hygienic, which makes it well suited to CNC EDM Drilling. We tune the process to the alloy so the finished 309S Stainless Steel EDM machining part meets your dimensional and functional requirements.