Aerospace covers commercial, military and space propulsion plus airframe structural systems. Jet engine hot zones endure extreme heat, cyclic thermal stress, oxidation and fatigue; components must retain mechanical strength at temperatures above 700°C. 

Nickel-base superalloys dominate engine hot-section parts, while stainless steels are specified for auxiliary, control and cryogenic assemblies.

Alloy 718 (UNS N07718) is the most widely used superalloy for turbine discs, compressor parts, shafts, high-strength fasteners and valve components. 

Alloy 625 serves exhaust ducts, thrust reverser structures and bellows requiring fatigue and oxidation resistance. Hastelloy X (UNS N06002) is selected for combustor cans, flame holders and afterburner liners. Waspaloy is used for high-pressure turbine rotating components for advanced engines. 

Alloy 80A (Nimonic 80A, UNS N07080) is deployed for turbine blades, high‑temperature bolts, retaining rings.

Precipitation hardening stainless steel 15-5PH (S15500) is used for landing gear fittings, hydraulic valve bodies and high-strength airframe fasteners. Austenitic 316L stainless steel applies to cryogenic fuel lines, instrument tubing and ground-support assemblies. All grades satisfy AMS aerospace specifications, delivering consistent creep, fatigue and corrosion resistance under severe flight-cycle loading.