A newly developed nickel-free, high strength austenitic stainless steel (EN 1.4678) offers excellent ductility and corrosion resistance. While its primary use is in automotive applications, its superior mechanical properties, combined with its affordability, make it an attractive material for structural applications such as structural connections which require both high strength and ductility. This paper reports, for the first time, structural tests of T-stubs made of grade EN 1.4678 under static loading conditions. Tests on similar specimens made of conventional austenitic stainless steel EN 1.4307 and carbon steel S355 are reported for comparison. A total of 10 tests are reported, and the effects of varying the T-stub flange material, bolt grade, and bolt spacing are analysed. Digital image correlation has been employed to monitor and record the strains and cracks of the tested specimens evolving during testing. A finite element model was also developed and validated against the obtained test results. Thereafter, parametric studies were conducted to expand the range of available data over a wider range of geometries and material combinations. The design specifications for equivalent T-stubs in tension in Eurocode 3 prEN1993-1-4 and EN1993-1-8 are assessed on the basis of experimental and numerical results, and cases where the specifications are inaccurate or potentially unsafe are highlighted. A simple modification of the existing design model is proposed, which offers more consistent ultimate capacity predictions without compromising the simplicity of the current design framework.