Alloy 15-5PH, or as also referred to by XM-12 or UNS S15500, is a modified version of 17-4 PH. Belonging to the martensitic category of stainless steels, the alloy is a precipitation hardening type. The refined microstructure that has been achieved through a remelting process, is the reason for the improvement in the toughness property of 15-5PH Bolts. A specification which covers the chemical, as well as mechanical requirements for fasteners in stainless steel grade 15-5PH, is the ASTM F2281.
The 15-5 PH Fasteners are used in those applications where the primary requirements include superior resistance to heat along with good corrosion resistance and toughness. The ASTM F2281 15-5 PH Nuts has a low temperature hardening in combination with good fabrication properties and excellent resistance to corrosion, which makes this Martensitic stainless steel well suited to be used for applications in many industries.
The UNS S15500 is an alloy that can be machined either in a solution annealed condition or in the final heat treat condition. The tensile strength and ductility of UNS S15500 Stud Bolts are properties which can be enhanced by heating the alloy at different temperatures. The products such as 15 5 PH Stainless Steel Screws according to the ASTM F2281 specification is to be subject to not only a chemical analysis, but also several mechanical tests that can be used to determine yield strength and wedge tensile strength, or axial tensile strength. Moreover, these fasteners are also to undergo corrosion resistance tests in order to determine freedom from precipitated carbides.