17-4 PH Stainless Steel
17-4 PH is a precipitation-hardening stainless steel combining high strength, moderate corrosion resistance and relatively simple aging heat treatment.
Grade overview
The alloy is martensitic after solution treatment and strengthened by copper-rich precipitation during aging.
Typical applications
Shafts, valve parts, aerospace hardware, pump components, molds, fasteners and high-strength stainless machinery parts.
Equivalent / related designations
UNS S17400 and EN 1.4542 are widely used designations. Mechanical properties depend strongly on aging condition such as H900, H1025 or H1150.
Common manufacturers and supply
Produced by specialty stainless and aerospace alloy mills including Carpenter Technology, Böhler/voestalpine, Aubert & Duval and others.
Fabrication and selection notes
Confirm the exact product standard, edition, dimensions, delivery condition, mechanical properties, impact requirements, heat treatment, welding procedure, corrosion environment and certification. A grade name alone is not sufficient for procurement or design approval.
QA/QC documentation
For critical service, verify heat number traceability, mill test certificate, chemical analysis, tensile/impact results where required, NDT, heat-treatment record and project-specific third-party inspection requirements.
Element Folio engineering reference. Requirements vary by standard edition, product form and manufacturer; verify the latest governing specification.

