VT machining offers CNC Milling for 420 Stainless Steel (UNS S42000 / 1.4021-1.4034), typically supplied annealed or hardened. Higher carbon than 410 reaches greater hardness; machined annealed then hardened.
CNC Milling Notes for 420 Stainless Steel
420 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 420 Stainless Steel weighs about 0.77 kg.
Starting Parameters for CNC Milling 420 Stainless Steel
| Cutting speed (carbide) | 100-185 m/min |
|---|---|
| Feed per tooth | 0.028-0.088 mm |
| Spindle speed, Ø10 mm end mill | 3180-5890 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 | 10.3 µm (CTE 10.3 µm/m·K) |
Starting values for 420 Stainless Steel, Annealed or hardened; optimised on the first article.
420 Stainless Steel Data Relevant to CNC Milling
| Equivalent designations | UNS S42000 / 1.4021-1.4034 |
|---|---|
| Key composition | Cr 12-14%, C 0.15-0.4% |
| Typical supply condition | Annealed or hardened |
| Hardness (typical) | Up to ~50 HRC |
| Machinability rating | 45% (AISI B1112 = 100%) |
Typical values; we work to your drawing and mill certificate.
How 420 Stainless Steel Differs
Higher carbon than 410 reaches greater hardness; machined annealed then hardened.
Typical applications: Surgical instruments, molds, knife blades.
420 Stainless Steel vs Similar Grades
| 420 Stainless Steel | 416 Stainless Steel | 430 Stainless Steel | 410 Stainless Steel | |
|---|---|---|---|---|
| Key composition | Cr 12-14%, C 0.15-0.4% | Cr 12-14%, S ≥0.15% | Cr 16-18% | Cr 11.5-13.5% |
| Hardness | Up to ~50 HRC | ~20 HRC annealed; up to ~40 HRC | ≤88 HRB | ~20 HRC annealed; up to ~45 HRC hardened |
| Tensile (MPa) | ≥655 annealed | ≥485 annealed | ≥450 | ≥450 annealed |
| Machinability % | 45 | 85 | 54 | 55 |
| Typical use | Surgical instruments, molds, knife blades | Screw-machine parts, valve stems, gears, motor shafts | Appliance panels, trim, magnetic parts | Valve trim, pump shafts, cutlery, fasteners |
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 420 Stainless Steel
Send a STEP/IGES model or PDF drawing, confirm 420 Stainless Steel and its condition (we usually see it supplied annealed or hardened), the quantity, critical tolerances and any finish or certificate requirements.
420 Stainless Steel in Other Processes
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Send the drawing, the 420 Stainless Steel condition and the quantity — pricing and lead time come back the same or next business day.
Request a QuoteFrequently Asked Questions
What tolerances can you hold for CNC Milling 420 Stainless Steel?
Achievable tolerances for 420 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 is the typical lead time and minimum order for CNC Milling 420 Stainless Steel?
CNC Milling prototypes for 420 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 420 Stainless Steel a good choice for CNC Milling?
420 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 420 Stainless Steel machining part meets your dimensional and functional requirements.
Which industries use CNC Milling 420 Stainless Steel parts?
CNC Milling 420 Stainless Steel parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise 420 Stainless Steel components are required.
What is CNC Milling 420 Stainless Steel and how is it done?
CNC Milling 420 Stainless Steel refers to multi-axis milling cutters remove material to produce prismatic features, pockets, slots and contoured 3D surfaces. Applied to 420 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.