Materials
PH Stainless Steel: 15-5
15-5 PH Stainless Steel (UNS S15500)
Material: A precipitation-hardening (PH) martensitic stainless steel derived from 17-4PH chemistry but refined for improved toughness and transverse properties. Contains chromium, nickel, copper, and small amounts of niobium.
Designed for applications requiring high strength, good corrosion resistance, and excellent dimensional stability.
Mechanical Properties:
Very high strength after aging:
Typical tensile strength: ~150–190 ksi (depending on condition H900–H1150).
Yield strength can exceed ~140–170 ksi in higher-strength conditions.
Excellent fatigue strength and fracture toughness, especially compared to 17-4PH in similar strength ranges.
Good ductility, with improved toughness in thicker sections vs. other PH stainless steels.
Maintains strength and stability up to ~600°F (315°C) in many conditions.
Corrosion Resistance:
Good general corrosion resistance, comparable to 304 stainless steel in many environments, and slightly better in some chloride conditions.
Better resistance to stress corrosion cracking than many martensitic stainless steels.
Performs well in marine, aerospace, chemical, and industrial atmospheres, though not as corrosion resistant as 316 in severe chloride exposure.
Suitable for moderate seawater exposure with proper design considerations.
Manufacturing Considerations:
Supplied in solution-annealed condition and then age hardened (precipitation hardened) to achieve final properties.
Excellent dimensional stability during heat treatment (low distortion compared to conventional hardening steels).
Machinability is moderate; better than fully hardened steels but still work-hardening.
Weldable in the solution-annealed condition, followed by post-weld aging to restore properties.
Widely used for precision machining of tight-tolerance fasteners.
Applications in Fasteners & Components:
High-strength aerospace fasteners (bolts, pins, studs, and structural hardware).
Oil & gas components, including valves, wellhead equipment, and high-pressure connectors.
Marine and offshore hardware requiring a balance of strength and corrosion resistance.
Defense and firearms components, including load-bearing and wear-critical parts.
Industrial machinery where high strength and moderate corrosion resistance are required.
Key Takeaway for Engineered Fasteners
15-5 PH Stainless Steel is selected when engineers need very high strength combined with good corrosion resistance and superior toughness, especially in precision components. Compared to 17-4PH, it generally offers better toughness and transverse mechanical properties, making it a preferred choice for critical aerospace, defense, and high-performance industrial fasteners.
Materials
BRASS
BRONZE
COPPER
PH STAINLESS STEEL
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