This paper presents a comprehensive experimental study of ferritic stainless steel tubular crosssections under combined loading.Two square hollowsection (SHS) sizes – SHS 40×40×2 and SHS 50×50×2 in grade EN 1.4509 stainless steel were considered. In total, two concentric compression tests, ten uniaxial bending plus compression tests and four biaxial bending plus compression tests were carried out. The experimental results were analysed and then compared with the design strengths predicted by the current European code EN 1993-1-4 (2006) and American Specification SEI/ASCE-8 (2002), revealing undue conservatism. Recent proposals (Liew & Gardner 2014; Zhao et al. 2014a) have been made to extend the scope of the deformation-based Continuous Strength Method (CSM) to the case of combined loading. Their applicability to ferritic stainless steels was evaluated herein and substantial improvements in design efficiency were found.