AMS 5640 - 303 Stainless Steel Bars & Forgings
AMS 5640 covers 303 Stainless Steel bars and forgings. This alloy stands out because it fights off corrosion better than most, but you still get great machinability. That’s thanks to a bit of sulfur mixed in—enough to make it much easier to machine than regular 304 stainless. So, it’s perfect for parts where precision and speed matter, like shafts, valves, fittings, or fasteners in aerospace. When you use 303 Stainless Steel according to AMS 5640, you get solid corrosion resistance—good enough for most everyday and mildly aggressive environments. Just don’t use it for high-pressure vessels, since the sulfur can be a problem there. In its annealed form, it won’t attract a magnet, but after some cold work, you’ll notice a bit of magnetism.
Typical Applications of AMS 5640
AMS 5640 can be applied in :
- Aerospace fasteners, shafts, and precision components
- Industrial machinery requiring swaging, upsetting, or machining
- Screw machine industry parts, valves, and fittings
What is 303 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 where before it was tough and difficult to machine. 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.
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.