Edelstahl Eigenschaften

Stainless steel grades for CNC machining

Stainless steels span a wide range of machinability -- from free-cutting 303 to difficult-to-machine duplex and precipitation-hardening grades. Selecting the right grade for both performance and manufacturability is essential.

• 303 Stainless (Austenitic): 78% machinability -- best machining stainless. Sulphur addition improves chip breaking. Good corrosion resistance. Non-magnetic. Cannot be hardened by heat treatment.
• 304/304L Stainless (Austenitic): 50-55% machinability. Work-hardens rapidly. The most common stainless; excellent corrosion resistance. Use sharp carbide tools and consistent feed.
• 316/316L Stainless (Austenitic): 45-50% machinability. Molybdenum addition improves pitting resistance. Work-hardens severely. Low speeds, positive rake, rigid setup.
• 416 Stainless (Martensitic): 85% machinability -- best machining hardenable stainless. Magnetic. Can be hardened to 35-40 HRC. Used for valve parts, pump shafts.
• 17-4 PH (Precipitation Hardening): 45-55% machinability in annealed condition. Can be hardened to 40-47 HRC. Used for aerospace, chemical, and food processing. Machine in annealed condition, then heat treat.
• 2205 Duplex: 30-35% machinability. High strength and excellent corrosion resistance. Very difficult to machine -- work hardens, high cutting forces, abrasive to carbide. Low speeds, rigid setup, AlTiN-coated tools.

How to use this Stainless Steel Properties Reference Guide

Use this reference to compare stainless steel grades. 303 is the best choice for high-volume machined parts requiring corrosion resistance. 304/316 are the standard general-purpose stainless grades but require careful machining strategy. For the most difficult grades (duplex, PH), use premium carbide tooling and conservative cutting parameters.