VT machining offers CNC Milling for 309S Stainless Steel (UNS S30908 / 1.4833), typically supplied annealed. Low-carbon 309 for better weldability in high-temperature fabrications.
CNC Milling Notes for 309S Stainless Steel
309S Stainless Steel mills well with conventional strategies; finishing passes are planned to meet flatness and finish callouts.
For estimating, a 100 × 100 × 10 mm block of 309S Stainless Steel weighs about 0.79 kg.
Starting Parameters for CNC Milling 309S Stainless Steel
| Cutting speed (carbide) | 90-165 m/min |
|---|---|
| Feed per tooth | 0.028-0.088 mm |
| Spindle speed, Ø10 mm end mill | 2860-5250 rpm |
| Insert / tool class | ISO M — positive-rake PVD/CVD carbide |
| Coolant | Flood emulsion (8-10%) or high-pressure coolant |
| Thermal growth, 100 mm part, +10 °C | 16.5 µm (CTE 16.5 µm/m·K) |
Starting values for 309S Stainless Steel, Annealed; optimised on the first article.
309S Stainless Steel Data Relevant to CNC Milling
| Equivalent designations | UNS S30908 / 1.4833 |
|---|---|
| Key composition | Cr 22-24%, Ni 12-15%, C ≤0.08% |
| Typical supply condition | Annealed |
| Hardness (typical) | ≤95 HRB |
| Machinability rating | 40% (AISI B1112 = 100%) |
Typical values; we work to your drawing and mill certificate.
How 309S Stainless Steel Differs
Low-carbon 309 for better weldability in high-temperature fabrications.
Typical applications: Kiln fixtures, heat-treat baskets.
309S Stainless Steel vs Similar Grades
| 309S Stainless Steel | 309 Stainless Steel | 310 Stainless Steel | 304L Stainless Steel | |
|---|---|---|---|---|
| Key composition | Cr 22-24%, Ni 12-15%, C ≤0.08% | Cr 22-24%, Ni 12-15% | Cr 24-26%, Ni 19-22% | Cr 18-20%, Ni 8-12%, C ≤0.03% |
| Hardness | ≤95 HRB | ≤95 HRB | ≤95 HRB | ≤92 HRB |
| Tensile (MPa) | ≥515 | ≥515 | ≥515 | ≥485 |
| Machinability % | 40 | 40 | 36 | 45 |
| Typical use | Kiln fixtures, heat-treat baskets | Furnace parts, heat shields, burner components | Furnace components, radiant tubes | Welded assemblies, tanks, piping |
More on CNC Milling Stainless Steel
Finishing options, quality documentation and general cnc milling guidance for all stainless steel grades are on our CNC Milling Stainless Steel page.
No drawing yet? Sketch the part in our free 3D + 2D builder and send it with your RFQ.
Quoting CNC Milling 309S Stainless Steel
Send a STEP/IGES model or PDF drawing, confirm 309S Stainless Steel and its condition (we usually see it supplied annealed), the quantity, critical tolerances and any finish or certificate requirements.
309S Stainless Steel in Other Processes
Related
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
Why is 309S Stainless Steel a good choice for CNC Milling?
309S Stainless Steel is corrosion resistant, strong and hygienic, which makes it well suited to CNC Milling. We tune the process to the alloy so the finished 309S Stainless Steel machining part meets your dimensional and functional requirements.
How clean are the edges produced by CNC Milling 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 Milling 309S Stainless Steel?
Achievable tolerances for 309S Stainless Steel machining depend on the alloy, geometry and feature size. Milling holds positional and dimensional tolerances to around ±0.01 mm, tighter with precision setups. Exact figures are confirmed against your drawing callouts.
What surface finish is achievable on 309S Stainless Steel with CNC Milling?
Surface finish on 309S Stainless Steel is controlled to your specification; we confirm the achievable Ra against your callout.
Which industries use CNC Milling 309S Stainless Steel parts?
CNC Milling 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 Milling 309S Stainless Steel?
CNC Milling 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.