15-5PH Stainless Steel

15-5 PH is specified in applications where reliable strength and corrosion resistance must be maintained across the full section of a component — not just in the longitudinal direction. Typical uses include aircraft structural components, landing gear elements, aerospace fasteners and fittings, gas turbine shafts, gears and valve components in power generation, pump shafts and impellers in chemical processing environments, and drivetrain components in motorsport where fatigue resistance and corrosion resistance are both required.

Six precipitation hardening conditions — H900 through H1150 — give engineers direct control over the strength and toughness balance of finished components. Tensile strength ranges from 1310 MPa at H900 down to 931 MPa at H1150, with 0.2% proof stress from 1172 MPa to 724 MPa across the same range. Longitudinal elongation runs from a minimum of 10% at H925 through to 16% at H1150. Transverse elongation — the figure that most clearly distinguishes 15-5 PH from 17-4 PH — ranges from 6% minimum at H925 to 11% minimum at H1150, measured and certified per AMS 5659. These properties are consistent through large section sizes, a direct consequence of the remelting process mandated by the specification.

The chromium content of 14.00–15.50% forms a stable passive oxide layer that resists atmospheric and mild chemical corrosion across all heat treatment conditions from H900 through H1150. 15-5 PH performs reliably in the environments typically encountered in aerospace structural applications — humidity, salt atmosphere and mild chemical exposure — without requiring additional surface protection in most cases. In power generation, it is well suited to steam and mild process media environments. Corrosion resistance is meaningfully better than standard martensitic stainless grades, owing to the higher chromium content and the contribution of the copper addition to passive film stability.

Both AMS 5659 and AMS 5862 require production by consumable electrode remelting — either vacuum arc remelting (VAR) or electroslag remelting (ESR). This is not an optional process enhancement; it is written into the specification. The remelting process eliminates sulphide inclusions that would otherwise reduce transverse ductility and toughness, and it ensures consistent chemistry throughout the full cross-section of every bar, plate and forging. Every heat is subject to macrostructure examination and chemical analysis, with tensile properties verified after precipitation heat treatment. Full certification with traceability to the original remelt heat is supplied with every shipment.

• Bar — AMS 5659
• Plate and sheet — AMS 5862
• Available in solution annealed condition ready for customer age hardening
• No minimum order quantities on stock items
• Suitable for prototype development through to production requirements

Dynamic Metals supplies 15-5 PH to AMS 5659 as bar, wire and forgings, and to AMS 5862 as sheet, strip and plate up to 4 inches (102 mm) nominal thickness. All material is supplied in the solution heat-treated condition, ready for customer age hardening to the required H-condition. No minimum order quantities apply on stock items, making us equally suited to prototype development programmes and full production contracts.

15-5 PH should be machined in the solution annealed condition, before age hardening to the required H-condition. The copper addition within the composition aids chip formation, making the alloy more straightforward to machine than many higher-strength PH grades. Dimensional change during ageing is predictable and minimal, which allows complex geometries to be machined close to final dimensions before heat treatment. The alloy is weldable using standard TIG and MIG processes with appropriate filler selection; for joints requiring full mechanical properties, post-weld re-solution treatment and re-ageing is recommended. The niobium addition stabilises the microstructure during welding and reduces the risk of sensitisation. Applicable solution annealing and precipitation hardening parameters are defined within AMS 5659 and AMS 5862.

15-5 PH was developed to solve a specific limitation of 17-4 PH — inconsistent transverse properties in larger section sizes. By requiring consumable electrode remelting within the specification itself, the alloy delivers through-section consistency that standard air-melted grades simply cannot match. The six-condition ageing system gives engineers flexibility that most high-strength alloy steels do not offer — a single stock material can be processed to meet a range of different strength and toughness targets. Good fabricability in the annealed condition, combined with reliable corrosion resistance without surface coating, reduces both manufacturing complexity and total component cost for aerospace structural applications. Wide approval by major aerospace OEMs means qualification burden for new programmes is typically lower than for less established grades.

Dynamic Metals has supplied 15-5 PH to aerospace, power generation and motorsport customers since 1997. We hold certified stock to both AMS 5659 and AMS 5862, supplied with full material certification and traceability to the original VAR or ESR remelt heat. Our team can advise on condition selection, heat treatment parameters and specification requirements. No minimum order quantities apply — we can support development programmes and production contracts alike. AS9100 certified. Prompt UK delivery on standard stock sizes and custom requirements available.