Comparisons are made between the presented closed form solutions and buckling load predictions obtained using current design provisions. While by nature approximate, the solutions are shown to be highly accurate. Closed form solutions are presented for up to seven rows of fasteners longitudinally. A general variational buckling equation is derived followed by an energy-type method for calculating buckling loads for common end support conditions, including columns supported on flexible end tracks. The paper concludes with the analysis of built-up sections subject to flexural buckling. A framework is also presented for determining the effective torsion rigidity ( EI w, eff) of open built-up sections in non-uniform torsion. The use of two nested top tracks in the framing of an interior gypsum board. Closed form solutions are obtained for the effective torsion rigidity ( GJ eff) of built-up sections featuring closed loops. Cold formed steel (CFS) is used in loadbearing walls, non-load bearing walls. Next, the paper describes the linear analysis of built-up sections in torsion, considering first uniform torsion followed by non-uniform torsion. AISI Specifications: Comply with AISIs 'Specification for the Design of Cold-Formed Steel Structural Members' or 'Load and Resistance Factor Design Specification for Cold-Formed Steel Structural Members' and the following for calculating structural characteristics of cold-formed metal framing. Closed form solutions are provided for five load and end support cases to demonstrate the application of the analysis. COLD-FORMED METAL FRAMING 03/2016 Edition. The paper first outlines the linear analysis of beams in flexure and introduces the notion of the effective flexural rigidity to account for partial composite actions. By considering fasteners at discrete points, it is possible to analyse the effects of placing additional fasteners at the ends (end fastener groups), to account directly for actual support conditions and to determine the optimum locations of fasteners. The paper presents methods of analysis of built-up sections in which the discrete locations of fasteners is accounted for explicitly, rather than by smearing their effect using continuous shear flexibility as in current approaches.