The object of research is development of an algorithm that can be used as a tool in the design of space trusses made of round tubes. Method. At this stage the algorithm aims to work only with rolled round tubes according to Russian grades. In the first approximation the algorithm is divided into two components: reassignment of sections according to the selected assortment and unification to the required number of bars. At the end of the first stage, intermediate results can be uploaded to check how much the mass of the structure has increased. In addition, saving the intermediate results allows you not to restart the first stage if the initial data for the second stage has changed. Results. The algorithm which automates the assignment of sections according to a given assortment and optimized unification of section sizes to a given number of different rolled products and can be applied to any truss or space truss. For statically indeterminate rod systems where the longitudinal force is many times greater than the moment, this method can also be applied, but verification calculations will be required.