Strength, Corrosion Resistance,
Hygiene

Stainless steel is the material of choice when parts need to withstand harsh environments, maintain hygiene, or deliver high strength at elevated temperatures. It machines differently than aluminum — requiring lower speeds, more rigid setups, and specialized tooling.

At YEYUAN CNC, we have the rigid machine tools and carbide tooling required for clean, precise stainless steel machining. We understand the feeds, speeds, and coolant strategies that prevent work hardening, tool wear, and dimensional drift.

Precision CNC machined metal components

Stainless Steel Grades
We Machine

Stainless Steel 304

The most widely used stainless steel. Excellent corrosion resistance, good formability, and good machinability. The standard choice for general-purpose stainless parts.

Typical Applications: Food processing equipment, kitchen hardware, architectural panels, chemical containers, medical devices.

Stainless Steel 316L

Molybdenum-enhanced for superior corrosion resistance, especially against chlorides and acids. The low-carbon variant (316L) avoids carbide precipitation during welding.

Typical Applications: Marine hardware, pharmaceutical equipment, surgical implants, chemical processing, offshore oil & gas.

Stainless Steel 303

Free-machining grade with sulfur added for improved chip breaking. The best choice when extensive machining is required and corrosion resistance is secondary.

Typical Applications: Fittings, fasteners, bushings, shafts, and parts with threaded features requiring extensive machining.

Stainless Steel 17-4 PH

Precipitation-hardening martensitic stainless offering high strength (up to 1300 MPa) with good corrosion resistance after heat treatment.

Typical Applications: Aerospace components, pump shafts, valves, high-strength fasteners, nuclear waste processing.

Stainless Steel 420

Martensitic stainless that can be hardened to HRC 50+. Good corrosion resistance in hardened condition. Higher carbon content for wear resistance.

Typical Applications: Cutlery, surgical instruments, valve components, pump parts, molds, wear-resistant tooling.

Capability
Overview

CNC Capability 3-axis, 4-axis, 5-axis
Max Part Size 600 × 500 × 400 mm
Tolerance ±0.01 mm
Surface Finish Ra 0.8–3.2 µm
Lead Time 5–15 days (rush available)
Min Order 1 pc prototype
Surface Treatments Passivation, electropolishing, bead blasting, PVD coating
File Formats STEP, IGES, X_T, 2D PDF

Send your stainless steel part drawing. Quote in 24 hours.

Free DFM review. We'll recommend the right grade and flag any features that will drive up cost before we quote.

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Stainless Steel CNC
Knowledge Base

Stainless Steel CNC Machining
Common Questions

304 vs 316L — which do I need?

304 covers 90% of applications: food equipment, architectural, general industrial. Choose 316L if your parts face salt water, chlorides, or harsh chemicals. 316L costs about 20–40% more than 304 in raw material and machines slightly slower. If you're not sure, 316L is the safer choice — it does everything 304 does and more.

Why is stainless harder to machine than aluminum?

Stainless is tougher, gummier, and work-hardens. Cutting speeds are 3–5× slower than aluminum. Tool wear is faster. Coolant strategy matters — get it wrong and the surface burns or the tool snaps. This is why stainless parts cost more: it's not just material, it's machine time and tooling.

Do my stainless parts need passivation?

If corrosion resistance matters at all — yes. Passivation removes free iron from the surface and restores the chromium oxide layer. It's cheap (typically under $50 for a batch) and prevents rust spots. We recommend it on all stainless parts by default unless you tell us otherwise.

What's the lead time for stainless parts?

Typically 5–10 days for prototypes, 10–15 days for production runs. Stainless takes longer than aluminum at every step — machining, deburring, finishing. Rush service is available; we've done 3-day stainless prototypes for urgent jobs.

Can you machine hardened stainless?

17-4 PH in the annealed condition (HRC 28–32) machines fine — we machine it, then send out for heat treatment to H900 (HRC 40–47) or H1025. Already-hardened 420 at HRC 50+ is possible but slow and expensive. We use carbide tooling and conservative feeds for hardened material.

What surface finishes are available beyond passivation?

Electropolishing for a mirror-like Ra 0.2μm finish (great for food/pharma), bead blasting for a uniform matte look, and PVD coating for color options. We can also arrange electroplating (nickel, chrome) through partner shops. Just tell us what you need and we'll sort it out.

Get a Stainless Steel CNC Machining Quote — Free DFM Review

Send your drawing for custom stainless steel CNC parts in 304, 316L, 303, 17-4 PH, and 420. Precision machined components with passivation available — quoted within 24 hours.

✓ ISO 9001 Certified ✓ Free DFM Review ✓ Passivation Included ✓ CMM Inspection
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