This study presents a novel design methodfor determining the tensile load-bearing capacity of a rivet nut connection with an aluminium alloy profile. The method, developed based on the requirements of standards LVS EN 1993-1-8:2025, LVS EN 1999-1-1:2023, and LVS EN1999-1-4:2023, incorporates checks on the aluminium profile web’s shear strength, rivet and rivet nut capacities, thread strength, and profile web buckling. Twenty-five laboratory specimens across five groups - with web thicknesses ranging from 2 mm to 5 mm and utilising rivet nuts made of AISI 303 1.4305 stainless steel and AW 5052 H32 aluminium alloy - were tested. The aluminium profiles were grade AW 6060 T66. Results show that using stainless steel rivet nuts increased the elastic-stage load-carrying capacity (Fp0.2) by 18.33% and the ultimate load capacity (Fm) by 15.89% compared to aluminium alloy nuts. The proposed design algorithm, validated by experimental tests and finite element method (FEM) analyses using Dlubal RFEM 6 (v. 4), predicts tensile resistance within a 10% accuracy. The study identifies pull-out of the aluminium profile wall as a critical failure mechanism, emphasising its inclusion to avoid overestimating connection capacity. This method provides a practical and reliable design tool for tensile load-bearing rivet nut connections in aluminium structural systems.