Stainless Steel 303

Stainless Steel 303 is a free-machining austenitic stainless steel developed from 304 by increasing sulfur content to improve machinability. Its key advantages are excellent cutting performance, high machining efficiency, and good corrosion resistance, making it particularly suitable for high-volume CNC turning, milling, and precision components with extensive threaded features.

Appearance & Properties

Color: Silver-gray to bright silver

Density: Approx. 8.03 g/cm³

Tensile Strength: Approx. 620 MPa (typical annealed condition; varies by product form)

Corrosion Resistance: Good

Machinability: Excellent

Weldability: Poor

Magnetism: Generally non-magnetic when annealed; slight magnetism may develop after cold working

Surface Finishes: Polishing, brushing, bead blasting, passivation, electropolishing, etc.

Typical Applications

Stainless Steel 303 is widely used in automation equipment, electronics, automotive, machinery, medical equipment, and precision component manufacturing.

Typical parts include precision shafts, bolts, nuts, screws, bushings, fittings, valve components, gears, and various CNC turned parts.

Advantages

• Excellent machinability among stainless steels

• High machining efficiency for volume production

• Good dimensional accuracy and machined surface quality

• Good corrosion resistance

• Ideal for turned, threaded, and complex precision components

Limitations

• Generally lower corrosion resistance than 304 and 316

• Poor weldability

• Not ideal for highly corrosive or marine environments

• Not recommended for structures requiring extensive welding