MIL Specification 17-4PH Stainless Steel Stainless Steel

MIL-DTL-24527

17-4PH Stainless Steel – Military Specification

Precipitation-Hardening Stainless Steel, 17-4PH (UNS S17400), Military (Department of Defense) Specification

AS9100D / ISO 9001

Mill Test Reports

2–4 Week Delivery

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Quick Specification Facts

Spec Number MIL-DTL-24527

Material 17-4PH Precipitation-Hardening Stainless Steel

Spec Type Military Specification (MIL / Department of Defense)

Category 17-4PH Stainless Steel

Composition 15–17.5% Cr, 3–5% Ni, 3–5% Cu (UNS S17400)

Condition Various Heat Treatment Conditions (H900, H925, H1025, H1075, H1150)

Product Forms Bar, Plate, Sheet, Strip, Forgings

Certification AS9100D / ISO 9001 with full MTR traceability

Specification Overview

MIL-DTL-24527 is a Military (Department of Defense) Detail Specification covering 17-4PH precipitation-hardening stainless steel. This MilSpec applies to 17-4PH (UNS S17400) stainless steel and is used extensively in aerospace, naval, defense, and high-performance industrial applications requiring a combination of high strength, excellent corrosion resistance, and good toughness. The designation "17-4PH" refers to the nominal composition of 17% Chromium, 4% Nickel, and precipitation-hardening (PH) through the addition of Copper and Columbium (Niobium).

The alloy achieves its high strength through a two-stage heat treatment process: solution annealing (Condition A) followed by age hardening at temperatures ranging from 900°F to 1150°F, producing the H900, H925, H1025, H1075, and H1150 conditions. MIL-DTL-24527 material provides an outstanding combination of mechanical properties, corrosion resistance superior to standard 300-series stainless steels, and ease of fabrication, making it one of the most widely specified stainless steels in demanding military and aerospace programs.

Available Product Forms

Bar

Plate

Sheet

Strip

Forgings

MIL-DTL-24527 material is available in a full range of product forms including Bar, Plate, Sheet, Strip, and Forgings. We carry standard mill sizes and can provide custom-cut lengths and machined blanks from our in-house processing facility. Custom dimensions and near-net-shape forgings are available upon request. Contact our materials specialists for non-standard requirements.

Nominal Chemical Composition

Element	Symbol	Nominal %	Notes
Chromium	Cr	15.00 – 17.50%	Primary alloying element; provides corrosion resistance and hardenability
Nickel	Ni	3.00 – 5.00%	Stabilizes austenite; enhances toughness and corrosion resistance
Copper	Cu	3.00 – 5.00%	Key precipitation-hardening agent; enables age hardening response
Columbium + Tantalum	Nb+Ta	0.15 – 0.45%	Stabilizes martensite; refines grain structure
Carbon	C	0.07% max	Kept low to maintain corrosion resistance and toughness
Manganese	Mn	1.00% max	Deoxidizer; controlled for weldability
Silicon	Si	1.00% max	Deoxidizer; improves oxidation resistance
Iron	Fe	Balance	Base metal

Chemical composition ranges are nominal. Consult the current issue of MIL-DTL-24527 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	MIL-DTL-24527
Issuing Organization	U.S. Department of Defense (DoD) – Military Specification
Material Type	Precipitation-Hardening Stainless Steel
Steel Grade	17-4PH (UNS S17400 / AISI 630)
Nominal Composition	15–17.5% Cr, 3–5% Ni, 3–5% Cu, 0.15–0.45% Nb+Ta
Available Forms	Bar, Plate, Sheet, Strip, Forgings
Heat Treatment Conditions	Condition A (annealed), H900, H925, H1025, H1075, H1150, H1150-M
Tensile Strength (H900)	190 ksi (1310 MPa) typical minimum
Yield Strength (H900)	170 ksi (1170 MPa) typical minimum
Corrosion Resistance	Excellent – superior to standard 300-series austenitic grades in many environments
Weldability	Good – weldable by conventional methods; post-weld aging recommended
Magnetic Properties	Magnetic (martensitic in aged conditions)
Certification Available	AS9100D / ISO 9001, Certificate of Conformance, MTR

Typical Applications

Aerospace & Defense: Aircraft structural components, actuators, fasteners, landing gear parts, helicopter rotor hubs, missile components, and high-strength structural assemblies requiring corrosion resistance and high strength-to-weight ratio.

Naval & Marine: Shipboard hardware, submarine components, deck fittings, pump shafts, valve bodies, and marine fasteners requiring excellent resistance to saltwater corrosion combined with high strength.

Medical & Surgical: Orthopedic implants, surgical instruments, dental components, and medical device hardware requiring biocompatibility, corrosion resistance, and high strength.

Oil & Gas: Valve stems, pump shafts, fittings, downhole tool components, and subsea equipment requiring high strength and resistance to corrosive environments.

Industrial & Chemical Processing: Pump and valve components, agitators, mixing equipment, and process hardware requiring a combination of strength, toughness, and corrosion resistance in aggressive chemical environments.

Frequently Asked Questions – MIL-DTL-24527

What is MIL-DTL-24527 and what does it cover?

MIL-DTL-24527 is a U.S. Department of Defense (DoD) Military Detail Specification covering 17-4PH precipitation-hardening stainless steel (UNS S17400 / AISI 630). It specifies requirements for chemical composition, mechanical properties, and quality for material supplied in bar, plate, sheet, strip, and forging forms. The specification is used extensively in naval, aerospace, and defense applications requiring high strength, excellent corrosion resistance, and good toughness. The 17-4PH designation reflects the nominal composition of 17% Chromium, 4% Nickel, with precipitation hardening achieved through Copper and Columbium additions.

What heat treatment conditions are available for MIL-DTL-24527 17-4PH?

MIL-DTL-24527 17-4PH stainless steel is available in multiple heat treatment conditions that offer a wide range of strength and toughness combinations. The primary conditions are: Condition A (solution annealed, lowest strength / highest ductility), H900 (aged at 900°F – highest strength, ~190 ksi UTS), H925, H1025, H1075, H1150, and H1150-M (double aged – highest toughness and corrosion resistance). As the aging temperature increases, strength decreases while ductility and corrosion resistance improve. Aero-Vac stocks material in multiple conditions and can provide heat treatment services in-house.

Does Aero-Vac supply MIL-DTL-24527 with full mill test reports and certifications?

Yes. All MIL-DTL-24527 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 military or defense program requires additional special process certifications, our quality team can coordinate as needed.

What product forms does Aero-Vac stock for MIL-DTL-24527?

Aero-Vac maintains inventory of MIL-DTL-24527 17-4PH stainless steel in a wide range of product forms including bar (round, square, flat), plate, sheet, strip, and forgings. We carry standard mill sizes across multiple heat treatment conditions and can provide custom-cut lengths from our in-house processing facility at the Port of Kalama. For non-standard dimensions or near-net-shape forgings, our team can source from our global supplier network. Contact us with your specific requirements for a prompt quote.

What are the typical lead times for MIL-DTL-24527 material?

In-stock MIL-DTL-24527 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 items requiring mill production or specific heat treatment conditions may require 4–8 weeks depending on quantity and dimensions. We prioritize urgent aerospace, naval, 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 MIL-DTL-24527 material?

Yes. Aero-Vac operates a complete in-house processing facility at our Port of Kalama location. For MIL-DTL-24527 17-4PH stainless steel, we offer precision saw cutting, surface grinding, turning, milling, and heat treatment services including solution annealing and age hardening to specified conditions. 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 MIL-DTL-24527 material or a custom quote?

Our stainless steel specialists can provide fast pricing, availability, and technical guidance for your MIL-DTL-24527 / 17-4PH requirements.