Howmet Aerospace makes highly engineered, mission-critical components for jet engines, aircraft structures, and commercial trucks. The company's core business is jet engine components — turbine airfoils (blades and vanes), seamless rolled rings, forgings, and structural castings made from advanced materials like nickel superalloys and titanium. These parts are used in virtually every major commercial and military engine program, including CFM's LEAP engines and Pratt & Whitney's GTF. Howmet reports four segments: Engine Products (~53% of revenue), Fastening Systems (~21%), Engineered Structures (~14%), and Forged Wheels (~13%, sold under the Alcoa Wheels brand). Howmet sells directly to OEM customers, primarily engine makers like GE Aerospace and RTX, airframe primes like Boeing and Airbus, and defense contractors. Howmet makes money by selling precision parts at premium prices under long-term agreements, winning positions on engine and airframe programs years before production begins and supplying parts for the life of the program. The business sells both original equipment parts and aftermarket spares — spares have grown from 11% to 21% of revenue since 2019 and tend to grow as the installed fleet ages. Howmet's manufacturing processes carry high fixed costs, so margins improve meaningfully as volumes rise. The company is investing heavily in new capacity, primarily for jet engine airfoils and gas turbine blades, to capture demand from aerospace production ramps and a surge in natural gas turbine orders driven by data center electricity demand.