15 – 5 PH® Stainless Steel Bar

UNS S15500 (XM-12)

Stainless steel 15 – 5 PH®, also known as UNS S15500 or XM-12, is a modification of 17-4 PH developed in the 60’s. UNS S15500 stainless steel has a more refined microstructure as a result of the remelting process in which it was developed. This refined structure enhances toughness, especially in the transverse direction of the material. UNS S15500 also has excellent corrosion resistance, good fabricating characteristics and low temperature hardening which makes Stainless Steel 15 – 5 PH® the preferred alloy for many industries.

The composition of UNS S15500 includes small amounts of carbon, manganese, phosphorus, columbium (or niobium), tantalum, silicon and sulfur. 15500 can be forged, welded and formed. Machining may be performed in the solution-annealed state or in the final heat treat condition. Desired mechanical properties such as ductility and strength can be achieved through heating the material at various temperatures.

UNS S15500 is a martensitic precipitation hardening grade. Martensitic stainless steels were designed as a type of alloy which is corrosion resistant and could also be hardened through heat treatment.

Industries that use 15500 include:

  • Aerospace
  • Chemical
  • Food processing
  • General metal working
  • Paper industries
  • Petrochemical

Products partially or completely constructed of 15500 include:

  • Aircraft components
  • Cylinders
  • Engine parts
  • Fittings
  • Gears
  • Hallow shafts
  • Marine gas turbine compressor sections
  • Paper mill equipment
  • Shafts
  • Valves
AMS 5659
VAR (Type) 1
Stocking Diameters 1/2” to 12-1/2”
Material Lengths

Up to 24’
Bar Specifications
Uns Type Ams Astm Federal Characteristics
S15500 15 – 5 PH® 5658
A-564 15 – 5 PH is similar to 17-4 but superior transverse ductility and toughness.
Chemistry Analysis
.07 1. .03 .015 1. 14. – 15.5 3.5 – 5.5 .5 2.5 – 4.5 Cb + Ta = 8xC Min – .45 Max M

15 – 5 PH® is a trademark of Armco Inc.
The information above is not warranted, guaranteed, or for design purposes.

The information above is not warranted, guaranteed, or for design purposes.

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