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Precipitation-Hardening Stainless · 15-5 PH
15-5 PH CNC Machining
Higher-toughness alternative to 17-4 PH — same precipitation-hardening approach with better transverse toughness. The go-to for aerospace and defense components where cross-grain properties matter.
15-5 PH Stainless at a glance
| UNS designation | S15500 |
| Yield strength (H900) | ~170 ksi |
| Tensile strength (H900) | ~190 ksi |
| Hardness (H900) | ~40–45 HRC |
| Toughness (vs 17-4) | Higher, particularly transverse |
Conditions we routinely machine:
Condition AH900H1025H1075H1150
Where we machine 15-5 PH Stainless
Capabilities
Industries served
Typical 15-5 PH Stainless parts
- Aerospace structural hardware
- Landing gear components
- Defense structural fittings
- High-toughness downhole components
Frequently asked questions
15-5 PH vs 17-4 PH — which for my part?
Nearly identical mechanically. 15-5 has better transverse toughness (cleaner steelmaking, remelted). Spec 15-5 when the drawing calls for it or when transverse properties matter; otherwise 17-4 is more common and often cheaper.
Do you keep 15-5 PH in stock?
17-4 PH is more commonly stocked; 15-5 typically sourced per job. Adds material lead time.