About 2024|High-strength aluminum with copper as the primary alloying element. Machines well with good chip formation, closer to
7075 than
6061 in how it cuts. Excellent fatigue resistance, which is why it shows up constantly in aerospace structural parts like fuselage and wing components. The tradeoff is poor corrosion resistance (much worse than 6061) and it’s essentially non-weldable. Typically needs protective coatings like Alclad in corrosive environments. Costs more than 6061, less than 7075, and sits between them in strength. If you need more strength than 6061 but your budget or application doesn’t justify 7075, 2024 is worth considering.