Metals & alloys · Ferrous alloys

15-5 PH stainless steel

A martensitic precipitation-hardening stainless steel with improved transverse toughness and forgeability relative to many 17-4 PH products.

Family
Precipitation-Hardening Stainless Steel
Record
Standard
Conditions
4
Sources
3
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01

Overview

Material class
Metals & alloys
Category
Ferrous alloys
Family
Precipitation-Hardening Stainless Steel
Product forms
Sheet/plate, Bar/rod

Composition

ConstituentMinMaxTypicalNote
Cr1415.514.8
Ni3.55.54.5
Cu2.54.53.5
Nb+Ta0.150.450.3
C0.070.03
FeBalance

02

Properties and conditions

Engineering properties

PropertyValueUnitCondition
Density7.8g/cm³Representative; verify product form and condition
Elastic modulus197GPaRepresentative; verify product form and condition
Yield strength900–1200MPaH900–H1150 range
Tensile strength1000–1310MPacondition dependent
Elongation6–16%Representative; verify product form and condition
Hardness31–44HRCRepresentative; verify product form and condition

Conditions

heat treatment

Condition A / solution treated

Solution-treated precursor condition.

ageing

H1025

Intermediate ageing condition.

ageing

H1150

Overaged condition with reduced strength and improved toughness.

ageing

H900

Peak-strength precipitation-hardened condition.

03

Processing and use

Processing

  • Solution treatment followed by precipitation ageing sets strength and toughness.
  • Final machining allowance should consider ageing distortion.

Applications

  • Aircraft fittings
  • Valves
  • Shafts
  • Fasteners

Selection considerations

  • Condition selection is as important as grade designation.
  • Chloride SCC and pitting limits remain below highly alloyed stainless grades.

04

Standards and related materials

Standards and designations

SystemDesignationNote
UNSS15500
AMS5659 / 5862product dependent
ASTMA564

05

Sources and context

Sources

Confirm the applicable specification, product form and condition before using values for design or procurement.

Supply and sustainability

Common aerospace stainless product but less universally stocked than 17-4 PH.

High scrap value and long service life; nickel and niobium recovery benefits segregated recycling.

Strategic context

Aerospace-grade corrosion-resistant strength with tunable ageing conditions.

Critical inputs: Nickel, Niobium

Basis: EU Critical Raw Materials Act (2024); USGS 2025 Critical Minerals List