Aluminum alloys are used in a wide range of engineering applications and are gaining increasing usage in the construction sector, offering high strength-to-weight ratios and good durability. In this paper, a series of stub-column tests on aluminum alloy box sections with and without internal cross stiffeners is carried out to investigate cross-section capacity and to explore the possible exploitation of strain hardening in design. All existing stub-column test results from the literature were also collected. A database containing the results from 346 tests on aluminum alloy stub columns of box, channel, and angle sections, with a wide range of cross-section slendernesses, was formed. The test strengths were compared with the design strength...