What material is equivalent to 1.4545 stainless steel?

Mar 17, 2026

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1.4545 stainless steel is a martensitic precipitation-hardening (PH) stainless steel-commonly known as 15-5 PH or X5CrNiCuNb15-5-4-with a composition comprising approximately 15% chromium, 5% nickel, and 3% to 4% copper, along with added niobium for grain refinement. This material offers high strength, high hardness, and good corrosion resistance, while exhibiting superior transverse toughness compared to the 17-4 PH alloy; its mechanical strength can be significantly enhanced through a single-step low-temperature aging or hardening heat treatment.

Standard	Designation / Grade
EN / DIN (Germany)	1.4545 / X5CrNiCuNb15-5
AISI/ASTM (USA)	15-5 PH
UNS (USA)	S15500
AFNOR (France)	EZ5CNU15-05
Common Trade Name	15-5PH, Custom 450 (Related)

Element	C	Si	Mn	P	S	Cr	Ni	Cu	Nb+Ta
Content (%)	≤ 0.07	≤ 1.0	≤ 1.0	≤ 0.04	≤ 0.03	14.0 - 15.5	3.5 - 5.5	2.5 - 4.5	0.15 - 0.45

Mechanical properties vary with heat treatment condition (e.g., Condition A, H900, H925, H1025, H1150).

Condition	Yield Strength (Rp0.2)	Tensile Strength (Rm)	Elongation (A)	Hardness (HRC)
Solution Treated (A)	~ 690 MPa	~ 1000 MPa	~ 15%	~ 32 HRC
H900 (480°C age)	~ 1170 MPa	~ 1310 MPa	~ 10%	~ 44 HRC
H1025 (550°C age)	~ 1070 MPa	~ 1170 MPa	~ 12%	~ 38 HRC
H1150 (620°C age)	~ 790 MPa	~ 1000 MPa	~ 12%	~ 33 HRC

Superior Toughness and Ductility: Offers significantly better transverse toughness and ductility than 17-4PH due to cleaner microstructure and optimized composition, with minimal property variation between longitudinal and transverse directions.

High Strength with Excellent Corrosion Resistance: Achieves tensile strengths over 1300 MPa after aging while maintaining corrosion resistance comparable to Type 304 stainless steel.

Precipitation Hardening: Can be machined in the solution-treated (softer) condition and then aged to high strength with minimal distortion, excellent for precision components.

Excellent Stress Corrosion Cracking Resistance: Better resistance to stress corrosion cracking than 17-4PH, particularly in the overaged (H1150) condition.

Aerospace: Structural components, landing gear parts, engine components.

Oil & Gas: High-pressure valves, pump shafts, and offshore equipment.

Medical: Surgical instruments and orthopedic implants.

Nuclear: Reactor components and fuel storage racks.

Both are precipitation-hardening martensitic stainless steels, but 15-5PH has slightly lower chromium (14–15.5% vs. 15–17.5%) and higher nickel content (3.5-5.5% vs. 3-5%). This composition adjustment, along with vacuum melting practices typically used for 15-5PH, results in cleaner steel with fewer inclusions, giving 15-5PH significantly better transverse toughness and ductility. 15-5PH also exhibits more isotropic properties (similar properties in all directions) and improved resistance to stress corrosion cracking. 15-5PH is often chosen for critical aerospace, nuclear, and medical applications where property consistency and reliability are essential.

The standard heat treatment involves solution treating at 1038°C ± 15°C, holding for sufficient time (typically 30 minutes minimum), followed by rapid cooling (air or oil quench) to achieve Condition A (soft, machinable state). It is then aged at a specific temperature depending on desired properties: 482°C for H900 (maximum strength), 496°C for H925 (good strength with improved toughness), 552°C for H1025 (balanced properties), or 621°C for H1150 (optimum toughness and stress corrosion resistance). Aging times are typically 4 hours, followed by air cooling. Double aging (H1150M) may be used to further improve toughness and dimensional stability. For critical applications, cryogenic treatment may be employed to minimize retained austenite.

Yes, 1.4545 is a martensitic stainless steel in its final structure, and it is strongly magnetic in all heat-treated conditions (Solution Annealed or Aged).

GNEE Steel supplies high-performance 15-5PH (1.4545) stainless steel in bar, plate, forging, wire, and precision ground forms, available in various heat-treated conditions (A, H900, H1025, H1150) to meet demanding aerospace and industrial specifications. We provide full material certification (EN 10204 3.1) and processing support including cutting, machining, grinding, and heat treatment services. If you have any requirements, please feel free to contact us.

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GNEE Supply Range (1.4545 / 15-5 PH)

GNEE can provide 1.4545 in various semi-finished forms with full certification (EN 10204 3.1).

Product Form	Specification / Dimensions
Round Bars	Diameter 6mm to 500mm (Rolled/Forged, Peeled or Polished)
Plates / Sheets	Thickness 2mm to 100mm (Hot Rolled, Annealed)
Forged Rings/Blocks	Custom sizes according to customer drawings
Condition of Supply	Solution Annealed (Cond. A) or Heat Treated (H900, H1025, H1150)
Testing Available	Ultrasonic (UT), Magnetic Particle (MPI), Impact Testing at Low Temp