ASTM Specification 15-5PH Stainless Steel XM-12

ASTM A564

15-5PH Stainless Steel – Age-Hardening Stainless Steel (XM-12)

Stainless Steel Bars, Wire, Forgings, Rings, and Extrusions
15Cr – 4.5Ni – 0.30Cb – 3.5Cu | Hot-Rolled · Cold-Finished · Age-Hardening

AS9100D / ISO 9001

Mill Test Reports

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Quick Specification Facts

Spec Number ASTM A564 (XM-12)

Material 15-5PH Stainless Steel

Spec Type ASTM (American Society for Testing and Materials)

Category 15-5PH Stainless Steel

Composition 15Cr – 4.5Ni – 0.30Cb – 3.5Cu

Condition Solution-Annealed or Age-Hardened

Product Forms Bars, Wire, Forgings, Rings, Extrusions

Certification AS9100D / ISO 9001 with full MTR traceability

Specification Overview

ASTM A564 / XM-12 covers 15-5PH precipitation-hardening stainless steel in the form of bars, wire, forgings, rings, and extrusions. This specification is issued by ASTM International and covers hot-finished or cold-finished rounds, squares, hexagons, bar shapes, angles, tees, and channels—produced by hot rolling, extruding, or forging. It is widely used in aerospace, defense, oil & gas, and high-performance industrial applications requiring a combination of high strength, good corrosion resistance, and excellent transverse properties.

Per ASTM A564, material of types other than XM-16, XM-25, and Type 630 shall be furnished in the solution-annealed condition, or in the equalized and oven-tempered condition. Types 630, XM-16, and XM-25 may be furnished in the solution-annealed or age-hardened condition. The nominal composition of 15% Chromium, 4.5% Nickel, 0.30% Columbium (Niobium), and 3.5% Copper provides outstanding strength-to-weight ratio and excellent resistance to stress corrosion cracking. The age-hardening treatment allows the material to be machined in the annealed condition and then hardened to high strength levels with minimal dimensional distortion.

Available Product Forms

Bars

Wire

Forgings

Rings

Extrusions

All product forms are supplied in the Solution-Annealed or Age-Hardened condition per ASTM A564 requirements. Hot-rolled and cold-finished forms are available. Custom sizes, lengths, and pre-machined forms are available upon request. Contact our materials specialists for non-standard dimensions.

Nominal Chemical Composition

Element	Symbol	Nominal %	Notes
Chromium	Cr	15%	Primary corrosion resistance
Nickel	Ni	4.5%	Austenite stabilizer, toughness
Copper	Cu	3.5%	Precipitation hardening agent
Columbium (Niobium)	Cb (Nb)	0.30%	Grain refinement and stabilization
Iron	Fe	Balance	Base metal
Carbon	C	0.07% max	Low carbon for improved corrosion resistance
Manganese	Mn	1.00% max	Deoxidizer
Silicon	Si	1.00% max	Deoxidizer

Chemical composition ranges are nominal. Consult the current issue of ASTM A564 for precise minimum/maximum requirements. Aero-Vac provides full mill test reports (MTRs) with certified chemistry for every order.

Key Properties & Specification Details

Property / Attribute	Details
Specification Number	ASTM A564 (XM-12)
Issuing Organization	ASTM International
Material Type	Age-Hardening Precipitation-Hardening Stainless Steel
Steel Grade	15-5PH (UNS S15500)
Nominal Composition	15Cr – 4.5Ni – 0.30Cb – 3.5Cu
Condition	Solution-Annealed or Age-Hardened (Hot-Rolled or Cold-Finished)
Available Forms	Bars, Wire, Forgings, Rings, Extrusions
Corrosion Resistance	Good – superior to standard 410 and comparable to 304 stainless in many environments
Machinability	Excellent in annealed condition; can be age-hardened after machining
Strength	Very high – tensile strength up to 200 ksi+ depending on aging condition
Magnetic Properties	Magnetic (martensitic structure)
Certification Available	AS9100D / ISO 9001, Certificate of Conformance, MTR

Typical Applications

Aerospace & Defense: Aircraft structural components, landing gear parts, high-strength fasteners, actuator components, and airframe fittings requiring high strength and good corrosion resistance in demanding environments.

Oil & Gas Equipment: Valve bodies, pump shafts, wellhead components, and downhole tools requiring high strength and resistance to corrosive media including H₂S and chloride environments.

Nuclear & Power Generation: Reactor components, nuclear waste handling equipment, and power plant hardware requiring a combination of strength, toughness, and corrosion resistance.

Medical & Semiconductor: Surgical instruments, medical device components, and semiconductor processing equipment requiring high surface finish capability and corrosion resistance.

High-Strength Fasteners & Hardware: Bolts, studs, pins, and shafts where high strength-to-weight ratio, good transverse mechanical properties, and minimal distortion during hardening are critical requirements.

Frequently Asked Questions – ASTM A564 / XM-12

What is ASTM A564 and what does it cover?

ASTM A564 is an ASTM International specification covering bars and shapes of age-hardening (precipitation-hardening) stainless steels. The XM-12 type designation refers to 15-5PH stainless steel (UNS S15500). The specification covers hot-finished or cold-finished rounds, squares, hexagons, bar shapes, angles, tees, and channels produced by hot rolling, extruding, or forging. With a nominal composition of 15% Chromium, 4.5% Nickel, 0.30% Columbium, and 3.5% Copper, 15-5PH provides an outstanding combination of high strength, good corrosion resistance, and excellent transverse mechanical properties compared to standard 17-4PH.

What is the difference between 15-5PH (XM-12) and 17-4PH (Type 630) in ASTM A564?

Both 15-5PH (XM-12) and 17-4PH (Type 630) are precipitation-hardening stainless steels covered under ASTM A564, but they differ in key ways: (1) 15-5PH has a lower chromium content (~15% vs ~17%) and lower nickel (~4.5% vs ~4%), giving it a more refined, fully martensitic microstructure with superior transverse toughness and ductility; (2) 17-4PH may contain some delta ferrite in its microstructure, which can reduce toughness in certain product forms—15-5PH was specifically developed to minimize delta ferrite; (3) 15-5PH is generally preferred for applications requiring excellent transverse mechanical properties, such as forgings and large-diameter bars where through-thickness properties are critical; (4) Both grades can be age-hardened to comparable strength levels through the same H-condition treatments (H900, H1025, H1075, H1100, H1150).

Does Aero-Vac supply ASTM A564 / XM-12 with full mill test reports and certifications?

Yes. All ASTM A564 / XM-12 (15-5PH) material supplied by Aero-Vac is fully traceable to mill test reports (MTRs) confirming chemical composition and mechanical properties per the specification. We are AS9100D/ISO 9001 certified with a 99.6% quality rating. Every order ships with certificates of conformance, material certifications, and chemical/mechanical test reports. Electronic delivery of all documentation is available for fast turnaround. If your program requires additional special process certifications, our quality team can coordinate as needed.

What forms and sizes of ASTM A564 / XM-12 does Aero-Vac stock?

Aero-Vac maintains inventory of ASTM A564 / XM-12 (15-5PH) in multiple product forms including bars (round, flat, and hex), wire, forgings, rings, and extrusions. We carry a range of standard sizes in both hot-rolled and cold-finished conditions, and can provide custom-cut lengths, discs, and blocks from our in-house processing facility at the Port of Kalama. For non-standard dimensions, our team can source from our global supplier network. Contact us with your specific size requirements and we will provide a prompt quote with availability and lead time.

What are the typical lead times for ASTM A564 / XM-12 material?

In-stock ASTM A564 / XM-12 (15-5PH) material is typically available for same-day or next-day shipment. For custom-cut or specially processed orders, our standard lead time is 2–4 weeks—significantly faster than the industry average of 8–12 weeks. Specialty forgings or items requiring mill production may require 4–8 weeks depending on quantity and form. We prioritize urgent aerospace and defense requirements and will always provide honest, upfront delivery estimates. Rush processing is available on select items.

Can Aero-Vac provide value-added processing for ASTM A564 / XM-12 material?

Yes. Aero-Vac operates a complete in-house processing facility at our Port of Kalama location. For ASTM A564 / XM-12 (15-5PH) stainless steel, we offer precision saw cutting (including disc and ring cutting), surface grinding, trepanning, turning, milling, and age-hardening heat treatment. We also provide comprehensive mechanical and non-destructive testing services in-house. Having all capabilities under one roof allows for faster turnaround, tighter quality control, and reduced overall cost compared to using multiple vendors. Contact us to discuss your specific processing requirements.

Need ASTM A564 / XM-12 material or a custom quote?

Our 15-5PH stainless steel specialists can provide fast pricing, availability, and technical guidance for your ASTM A564 requirements.