Aluminum alloy 7075 is mostly identified with superb strength, sometimes even comparable to some versions of steel. Its strength-to-weight ratio is good too, meaning that it provides high strength while still very light. So if you are looking for an alloy to use where the most strength is needed in an aircraft, this material is worth considering. Aluminum 2024 is also renowned for its high strength-to-weight ratio, but it is typically not as strong as 7075 aluminum. Then there are 6061 aluminum extrusions, which are the most versatile of the trio. Its combination of strength, corrosion resistance, weldability, and capability to be welded is excellent. Overall, each of these alloys can be used as aerospace extrusions, but you need to know where to place them for optimum results.