321 Stainless Steel per AMS 5557
The specification for 321 stainless steel hydraulic tubing, both seamless and welded, in the solution heat-treated condition is defined by AMS 5557. This titanium-stabilized, austenitic chromium-nickel stainless steel possesses superior resistance to intergranular corrosion, excellent oxidation resistance up to 1500 °F (816 °C), and high creep and stress-rupture strengths compared to 304 stainless steel.
Applications of AMS 5557
AMS 5557 tubing is for harsh environments when you require strength at elevated temperatures, good oxidation resistance, and consistent weldability.
Applications for AMS 5557 tubing include:
– Aerospace and jet engines: hydraulic tubing, bleed air ducting, and exhaust manifolds that require thermal cycling.
– Chemical processing: high-temperature heat exchanger tubing and piping for use in oxidizing and mildly reducing environments.
– Power generation: superheater and boiler tubing that requires resistance to stress rupture.
– Automobiles and motorsports: exhaust tubing and exhaust system components that require heat resistance.
– Oil and gas: instrumentation and control tubing in corrosive environments.
What is 321 Stainless Steel ?
321 Stainless Steel is a titanium stabilized chromium nickel austenitic stainless steel with corrosion resistance similar to 304/304L.
321 STAINLESS STEEL SPECIFICATIONS
SHEET SOLUTION HEAT TREATED
Annealed sheets offering excellent corrosion resistance and formability for demanding applications.
TUBING
Precision tubes designed for corrosion resistance and mechanical reliability in fluid systems.
321 BARS & FORGINGS
High-quality bars and forgings suitable for structural, machined, and high-stress components.
FEDERAL & MILITARY SPECIFICATIONS
Government-certified sheets ensuring performance and durability under critical service conditions.
OIL & GAS
Materials engineered to withstand sour gas, chloride stress, and harsh operating environments.
Certified Material for Critical Service
Materials produced and supplied to AMS 5510, AMS 5645, AMS 5689, and related specifications can be delivered with:
- Certificates of Compliance (CoC) confirming adherence to AMS and ASTM standards.
- Mill Test Reports (MTRs) specifying chemical composition, mechanical properties, and heat-treatment data.
- Traceability documentation from melt source to final product batch.
Such certification is essential for aerospace, oil & gas, and defense applications, where traceable quality assurance is required for safety and regulatory compliance.