CNC Turning Stainless Steel is a core capability at VT machining. We combine controlled turning with material-aware setup for Stainless Steel — an alloy that is corrosion resistant, strong, hygienic (304/316 grades) — to produce parts that meet your specification first time.
CNC Turning Capability for Stainless Steel
- Diameter tolerance to ±0.005 mm
- Concentricity within 0.01 mm
- OD/ID, threading, grooving
- Bar and chuck work
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.
How CNC Turning Stainless Steel Works
The Stainless Steel 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.
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 Turning Stainless Steel
| 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 Turning Quality & Inspection
Consistent quality comes from disciplined process control. Critical dimensions on Stainless Steel parts are checked in-process and verified at final inspection using calibrated instruments and, where required, CMM measurement. Full documentation — dimensional reports, mill certs, FAIR — is available when your programme needs it.
CNC Turning Tolerances & Surface Finish
Turned Stainless Steel 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.
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 Turning Stainless Steel
A few design choices make a real difference to cost and quality. Consistent diameters, standard thread forms and avoiding extremely long, slender features help Stainless Steel turned parts stay concentric and economical. If you send your model early, we will return practical DFM feedback before you commit to production.
Working with Stainless Steel
Stainless Steel offers a useful combination of properties: it is corrosion resistant, strong, hygienic (304/316 grades). Those characteristics shape how we approach turning — 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.
Secondary Operations & Finishing
We complete Stainless Steel components with the secondary steps your drawing calls for. We arrange heat treatment, surface treatment, marking and assembly as needed. Tell us the final spec and we will plan the full route so parts arrive ready to use.
Applications of CNC Turning Stainless Steel
CNC Turning of Stainless Steel 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.
How to Order CNC Turning Stainless Steel
Ordering Stainless Steel parts is straightforward. Provide the drawing, material, quantity and any certification needs. Our engineers reply — in English — with feasibility, pricing and a realistic lead time, usually within one business day.
Parts We Have Run in Stainless Steel
Three representative CNC Turning Stainless Steel jobs, with the callouts that actually drove the process plan. Yours will differ — these are here so you can judge whether your part is in our range before you spend time on an RFQ.
Connector pin
- Material
- Stainless Steel
- Size
- Ø3.0 × 24 mm
- Key callouts
- OD ±0.005 mm, straightness 0.02 mm over length
- Batch
- 20,000 pcs
Swiss-turned from bar with a guide bushing; nothing else holds Ø3 mm over 24 mm.
Threaded fitting
- Material
- Stainless Steel
- Size
- Ø22 hex × 38 mm
- Key callouts
- G3/8" thread class 4h, bore H8, sealing face Ra 0.8 µm
- Batch
- 2,500 pcs
Run on a sub-spindle lathe so the back face is finished without a second setup.
Precision shaft
- Material
- Stainless Steel
- Size
- Ø16 × 240 mm
- Key callouts
- OD h6, concentricity 0.01 mm TIR, keyway 5 H9
- Batch
- 1,000 pcs / year
Turned between centres so both journals share one datum.
Finishing Options for 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 Turning 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 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.
Other Metals for CNC Turning
Other Processes for Stainless Steel
Send the drawing, the Stainless Steel 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 CNC Turning Stainless Steel and how is it done?
CNC Turning Stainless Steel refers to cNC turning rotates the workpiece against a single-point tool to produce cylindrical features, threads and grooves. Applied to Stainless Steel — corrosion resistant, strong, hygienic (304/316 grades) — 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 Turning on Stainless Steel?
Machined Stainless Steel edges are clean and to specification; edge-break or deburring is added when your drawing calls for it.
Why is Stainless Steel a good choice for CNC Turning?
Stainless Steel is corrosion resistant, strong, hygienic (304/316 grades), which makes it well suited to CNC Turning. We tune the process to the alloy so the finished Stainless Steel turning part meets your dimensional and functional requirements.
What tolerances can you hold for CNC Turning Stainless Steel?
Achievable tolerances for Stainless Steel 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 is the typical lead time and minimum order for CNC Turning Stainless Steel?
CNC Turning prototypes for 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.
Which industries use CNC Turning Stainless Steel parts?
CNC Turning Stainless Steel parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise Stainless Steel components are required.