VT machining offers CNC Milling for 431 Stainless Steel (UNS S43100 / 1.4057), typically supplied hardened & tempered. Best corrosion resistance of the martensitic grades with high toughness.
CNC Milling Notes for 431 Stainless Steel
431 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 431 Stainless Steel weighs about 0.77 kg.
Starting Parameters for CNC Milling 431 Stainless Steel
| Cutting speed (carbide) | 80-150 m/min |
|---|---|
| Feed per tooth | 0.028-0.088 mm |
| Spindle speed, Ø10 mm end mill | 2550-4770 rpm |
| Insert / tool class | ISO H — CBN or fine-grain carbide |
| Coolant | Flood emulsion (8-10%) or high-pressure coolant |
| Thermal growth, 100 mm part, +10 °C | 10.2 µm (CTE 10.2 µm/m·K) |
Starting values for 431 Stainless Steel, Hardened & tempered; optimised on the first article.
431 Stainless Steel Data Relevant to CNC Milling
| Equivalent designations | UNS S43100 / 1.4057 |
|---|---|
| Key composition | Cr 15-17%, Ni 1.25-2.5% |
| Typical supply condition | Hardened & tempered |
| Hardness (typical) | ~25-40 HRC |
| Machinability rating | 45% (AISI B1112 = 100%) |
Typical values; we work to your drawing and mill certificate.
How 431 Stainless Steel Differs
Best corrosion resistance of the martensitic grades with high toughness.
Typical applications: Pump shafts, marine fittings, aircraft fasteners.
431 Stainless Steel vs Similar Grades
| 431 Stainless Steel | 430 Stainless Steel | 440C Stainless Steel | 420 Stainless Steel | |
|---|---|---|---|---|
| Key composition | Cr 15-17%, Ni 1.25-2.5% | Cr 16-18% | Cr 16-18%, C 0.95-1.2% | Cr 12-14%, C 0.15-0.4% |
| Hardness | ~25-40 HRC | ≤88 HRB | Up to ~58-60 HRC | Up to ~50 HRC |
| Tensile (MPa) | ~860 (H&T) | ≥450 | ≥760 annealed | ≥655 annealed |
| Machinability % | 45 | 54 | 40 | 45 |
| Typical use | Pump shafts, marine fittings, aircraft fasteners | Appliance panels, trim, magnetic parts | Bearings, valve seats, nozzles, knives | Surgical instruments, molds, knife blades |
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 431 Stainless Steel
Send a STEP/IGES model or PDF drawing, confirm 431 Stainless Steel and its condition (we usually see it supplied hardened & tempered), the quantity, critical tolerances and any finish or certificate requirements.
431 Stainless Steel in Other Processes
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Send the drawing, the 431 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 431 Stainless Steel parts to my drawing?
Yes. 431 Stainless Steel 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 CNC Milling 431 Stainless Steel and how is it done?
CNC Milling 431 Stainless Steel refers to multi-axis milling cutters remove material to produce prismatic features, pockets, slots and contoured 3D surfaces. Applied to 431 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.
Which industries use CNC Milling 431 Stainless Steel parts?
CNC Milling 431 Stainless Steel parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise 431 Stainless Steel components are required.
What is the typical lead time and minimum order for CNC Milling 431 Stainless Steel?
CNC Milling prototypes for 431 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.