303 Stainless Steel - Free Machining Austenitic Stainless Steel
Stainless Steel 303 is a free machining stainless steel. Due to the addition of sulfur this 18-8 chrome nickel stainless steel has enhanced machinability. Stainless Steel 303 is widely used in the screw machine industry, as well as for use in shafts, valves and fittings. Stainless Steel 303 is not recommended for vessels containing gases or liquids under high pressure.
Product Forms & Size Range
303 Stainless Round Bar diameters range from 0.125″ to 14.00″ diameter.
flat bar comes in a variety of thicknesses and widths. For more information please request a quote.
Plate Thickness ranges from 0.1875″ to 6.50″ Thick.
Stainless Sheet Thicknesses range from 0.0010″ to .170″ Thick.
Properties and Characteristics
- Free machining: Sulfur addition improves machinability without compromising corrosion resistance
- Austenitic structure: Non-magnetic in annealed condition; can become slightly magnetic when cold worked
- Corrosion resistance: Performs well in moderate environments but not recommended for high-pressure vessels containing gases or liquids
- Mechanical properties: Achieves good strength, toughness, and ductility, with excellent dimensional stability during machining
Applications
The specification is widely used in:
- Aerospace and defense components
- Shafts, screws, and fasteners
- Precision valves and fittings
- Industrial machinery requiring high machinability
- Automotive and marine hardware
303 STAINLESS STEEL SPECIFICATIONS
BARS & FORGINGS
High-strength bars and forgings for precision-machined parts.
Certified Material for Critical Service
303 Stainless Steel is available as certified material for critical service applications. This means that every batch is tested and documented to meet aerospace, defense, and industrial standards, ensuring compliance with chemical composition, mechanical properties, and dimensional tolerances.
Certification typically includes:
- Mill Test Reports (MTRs) verifying chemical and mechanical properties
- Compliance with AMS, MIL, and QQ specifications
- Traceability from raw material to finished product
- Assurance for use in high-performance, safety-critical components
By using certified 303 Stainless Steel, manufacturers and engineers can ensure reliable performance in critical applications, from aerospace fasteners to precision machinery, where material integrity and consistency are essential.