<p>This research investigates the evolution in the application of Cold-Formed Steel (CFS) sections over the past decades, transitioning from their traditional use in purlin and girt members to a prevalent preference for constructing primary structural elements like beams and columns. The study focuses on the pivotal role of the cross-sectional shape and thickness of CFS sections in determining the bending strength of the beam. Specifically, it examines the influence of thickness on the bending strength of stiffened and double-stiffened plain and lipped channel sections, considering the thicknesses of 1.0&#xa0;mm, 1.5&#xa0;mm, 2.0&#xa0;mm, 2.5&#xa0;mm, and 3.0&#xa0;mm. Two distinct types of stiffeners are analyzed in this investigation: the first involves a stiffener positioned at the neutral axis, while the second introduces an additional stiffener between the neutral axis and top flange (double stiffener) in the form of a horizontal V-shape. Numerical and experimental analyses are employed to reveal the bending behavior of stiffened plain and lipped CFS beams. Furthermore, the study delves into the moment-rotation behavior, and bending stiffness. The findings underscore that the inclusion of a stiffener in the C-section significantly enhances its bending capacity, with noteworthy emphasis on the stiffener placed at one-fourth of the distance from the top flange, resulting in a substantial increase in flexural strength.</p> Graphical abstract <p></p>