Research on the interconnection of widely spaced back-to-back angles has not been conducted. This research was carried out with the aim of developing rules for the design and spacing of interconnectors in such members. Four parameters—the number of interconnectors, the back-to-back spacing between angles, the weld pattern used to connect the interconnectors to the angles, and the thickness of the interconnectors—were studied. The experimental and the theoretical results for the slender double angles confirm that only one interconnector, of practical proportions, is required to make the widely spaced angles act as an integral unit. Both the separation between angles, within reason, and the weld pattern used to connect the interconnectors to the angles had an insignificant effect on the failure load and the failure mode. The thickness of the interconnector did affect the load-carrying capacity of the strut, but only when the thickness of the interconnector was impractically small. The forces and moments in the interconnectors are very small. Key words: angles, back-to-back, buckling, building (codes), columns (structural), design interconnection.