Composition & metallurgy

Chromium-nickel systems strengthened by copper, aluminium, titanium, niobium or related precipitate-forming additions.

Common grades

17-4PH (UNS S17400), 15-5PH, 13-8Mo and 17-7PH.

Applications

Aerospace hardware, shafts, valve parts, fasteners, molds, petrochemical equipment, nuclear components and high-strength corrosion-resistant mechanisms.

Engineering characteristics

High strength with useful corrosion resistance and relatively predictable dimensional response during aging. Properties vary strongly with heat-treatment condition such as H900, H1025 or H1150 for 17-4PH.

Known manufacturers

Specialty stainless and aerospace producers include Carpenter Technology, ATI, Böhler/voestalpine, Aubert & Duval, Daido Steel and qualified stainless bar/forging mills.

Specification checks

Confirm the current standard revision, exact product form, heat-treatment condition, mechanical properties, impact requirements where applicable, corrosion environment, welding procedure, dimensions, tolerances, NDT and mill test certification. Similar designations across standards are not automatically equivalent.

Element Folio engineering reference. Manufacturer examples are indicative and product availability changes by plant, region and year.