15-5 PH Stainless Steel Shafts

Precipitation-hardening stainless — high strength and toughness, a cleaner-machining cousin of 17-4.

At a glance

Stocked condition	Cold finished (Condition A; age to H900–H1150 after machining)
Machinability	Fair-to-good for a PH grade
Weldability	Weldable (PH grades weld better than martensitic 416)
Corrosion resistance	Very good — comparable to 304
Hardening	Precipitation-hardens with a low-distortion aging cycle
Density (nominal)	0.283 lb/in³
Food contact	Not typical
Magnetic	Yes (martensitic PH)

15-5 PH delivers the same value proposition as 17-4: stainless corrosion resistance in the 304 class, combined with strength that plain austenitic grades cannot approach, unlocked by a low-temperature aging treatment after machining. Its more refined (ferrite-free) structure gives it better toughness across the grain and slightly nicer machining behavior.

Specify it where 17-4 would otherwise live — aerospace fittings, high-load pump and valve internals — especially when transverse toughness or a 15-5 print callout is in play.

Configure a 15-5 PH part →

Any geometry in the configurator — diameters, threads, keyseats, grooves, holes, tapers — can be machined in 15-5 PH. Pick the material in the sidebar and the price updates live.

When to choose 15-5 PH

The print says 15-5, or transverse toughness matters.
High strength plus stainless corrosion resistance in one material.
Aged hardness is needed with minimal distortion after machining.

Consider instead

17-4 PH — the more common PH grade, usually interchangeable.
316 — when corrosion, not strength, is the driver.
4140 — when corrosion resistance is not required at all.

Typical applications

Aerospace shafts and fittings
High-pressure valve stems
Pump shafts under high load
Actuator and landing-gear components

Frequently Asked Questions

They are close relatives with similar strength and corrosion resistance. 15-5's ferrite-free structure gives better through-thickness toughness and slightly cleaner machining; in practice you pick whichever the print calls out.

By precipitation hardening: a single low-temperature aging cycle (H900 to H1150) applied after machining. The low temperature means minimal distortion, so machined tolerances survive.

We supply parts machined in Condition A, ready for aging. The aging step is quick and low-distortion, done by you or your heat treater to the condition your load case needs.

Stocked as 15-5 PH CF — cold finished (Condition A). Material and condition are paired — each grade ships in one condition optimized for our process; see all grades on the materials page.