
Short answer: 15-5 PH is a precipitation-hardening martensitic stainless steel — essentially 17-4 PH with less ferrite for better transverse toughness — that reaches 1310 MPa after a simple single-step age at 480 °C (H900) and is used for aerospace fittings, valve parts and shafts.
At a Glance

Composition & Why It Exists
15-5 PH contains about 15% chromium, 5% nickel and 3–5% copper with niobium, remelted to minimise delta ferrite. That refinement gives it better transverse ductility and toughness than 17-4 PH at equal strength, which matters in forged and thick sections from our Forging Supplier programme. It belongs to the martensitic family described in Martensitic Vs Austenitic Stainless and sits alongside the grades in Explicação das classes de aço inoxidável.
Heat Treatment Conditions
Supplied in Condition A (solution-annealed), it is machined then aged in one step: H900 for maximum strength, H1025 and H1075 for a strength/toughness balance, H1150 for maximum toughness and stress-corrosion resistance. No quench is needed and distortion is minimal — a major advantage over the routes in Stress Relieving Vs Annealing. Impact behaviour should be verified per Charpy Impact Test Guide, and hardness confirmed with the methods in Metal Hardness Testing Methods.
Applications & Fabrication
Aerospace fittings and actuators, valve stems and gate components, pump shafts, moulds and high-strength fasteners (see Stainless Steel Fasteners Guide). Machine in Condition A where possible via our Cnc Machining Supplier capability, then age. Corrosion resistance sits between 410 and 304 — good in atmosphere and mild chemicals but below Stainless Steel 316 Properties in chlorides; passivate after machining per Passivation Vs Pickling.
Get a Quote
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Perguntas frequentes
It is a precipitation-hardening martensitic stainless steel with roughly 15% chromium, 5% nickel and 3–5% copper, refined to minimise delta ferrite for better transverse toughness.
15-5 PH has essentially the same strength as 17-4 PH but a lower delta-ferrite content, giving improved transverse ductility and toughness in forgings and heavy sections.
About 1310 MPa tensile and 44 HRC in the H900 condition, falling to roughly 930 MPa and 30 HRC at H1150 where toughness is prioritised.
Yes. HXSCO supplies 15-5 PH in bar, plate and forged form in Condition A or aged to H900 through H1150 with mill certificates.
Source 15-5 PH from HXSCO
HXSCO supplies 15-5 PH stainless bar, plate and forgings in Condition A or aged to H900–H1150 with mill certificates. Send your size and condition for a quote.
