VT machining offers CNC Turning for 904L Stainless Steel (UNS N08904 / 1.4539), typically supplied annealed. Super-austenitic grade for sulfuric acid and seawater; very gummy to cut.
CNC Turning Notes for 904L Stainless Steel
On the lathe 904L Stainless Steel needs chip-breaker inserts and constant chip load to avoid long, stringy swarf.
For estimating, a 100 × 100 × 10 mm block of 904L Stainless Steel weighs about 0.80 kg.
Starting Parameters for CNC Turning 904L Stainless Steel
| Cutting speed (carbide) | 80-145 m/min |
|---|---|
| Feed | 0.08-0.25 mm/rev |
| Spindle speed, Ø25 mm bar | 1020-1850 rpm |
| Insert / tool class | ISO M — positive-rake PVD/CVD carbide |
| Coolant | Flood emulsion (8-10%) or high-pressure coolant |
Starting values for 904L Stainless Steel, Annealed; optimised on the first article.
904L Stainless Steel Data Relevant to CNC Turning
| Equivalent designations | UNS N08904 / 1.4539 |
|---|---|
| Key composition | Cr 19-23%, Ni 23-28%, Mo 4-5%, Cu 1-2% |
| Typical supply condition | Annealed |
| Hardness (typical) | ≤90 HRB |
| Machinability rating | 30% (AISI B1112 = 100%) |
Typical values; we work to your drawing and mill certificate.
How 904L Stainless Steel Differs
Super-austenitic grade for sulfuric acid and seawater; very gummy to cut.
Typical applications: Acid handling, heat exchangers, watch cases.
904L Stainless Steel vs Similar Grades
| 904L Stainless Steel | 17-4 PH Stainless Steel | 440C Stainless Steel | 431 Stainless Steel | |
|---|---|---|---|---|
| Key composition | Cr 19-23%, Ni 23-28%, Mo 4-5%, Cu 1-2% | Cr 15-17.5%, Ni 3-5%, Cu 3-5%, Nb | Cr 16-18%, C 0.95-1.2% | Cr 15-17%, Ni 1.25-2.5% |
| Hardness | ≤90 HRB | ~28-44 HRC by condition | Up to ~58-60 HRC | ~25-40 HRC |
| Tensile (MPa) | ≥490 | 930-1310 | ≥760 annealed | ~860 (H&T) |
| Machinability % | 30 | 48 | 40 | 45 |
| Typical use | Acid handling, heat exchangers, watch cases | Aerospace, oil & gas, medical instruments | Bearings, valve seats, nozzles, knives | Pump shafts, marine fittings, aircraft fasteners |
More on CNC Turning Stainless Steel
Finishing options, quality documentation and general cnc turning guidance for all stainless steel grades are on our CNC Turning Stainless Steel page.
No drawing yet? Sketch the part in our free 3D + 2D builder and send it with your RFQ.
Quoting CNC Turning 904L Stainless Steel
Send a STEP/IGES model or PDF drawing, confirm 904L Stainless Steel and its condition (we usually see it supplied annealed), the quantity, critical tolerances and any finish or certificate requirements.
904L Stainless Steel in Other Processes
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Send the drawing, the 904L Stainless Steel condition and the quantity — pricing and lead time come back the same or next business day.
Request a QuoteFrequently Asked Questions
Can VT machining make custom 904L Stainless Steel parts to my drawing?
Yes. 904L Stainless Steel 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.
What surface finish is achievable on 904L Stainless Steel with CNC Turning?
Surface finish on 904L Stainless Steel is controlled to your specification; we confirm the achievable Ra against your callout.
Why is 904L Stainless Steel a good choice for CNC Turning?
904L Stainless Steel is corrosion resistant, strong and hygienic, which makes it well suited to CNC Turning. We tune the process to the alloy so the finished 904L Stainless Steel turning part meets your dimensional and functional requirements.
Does CNC Turning 904L Stainless Steel require dedicated tooling?
Most 904L Stainless Steel turning work uses standard cutting tools and CNC programs; dedicated fixtures are made only when geometry or volume requires them.
Which industries use CNC Turning 904L Stainless Steel parts?
CNC Turning 904L Stainless Steel parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise 904L Stainless Steel components are required.
What is CNC Turning 904L Stainless Steel and how is it done?
CNC Turning 904L Stainless Steel refers to cNC turning rotates the workpiece against a single-point tool to produce cylindrical features, threads and grooves. Applied to 904L Stainless Steel — corrosion resistant, strong and hygienic — VT machining produces each part to your CAD drawing, selecting parameters from your tolerance, finish and quantity requirements.