The paper considers the basic conditions that allow changing the compactness of metal deployable structures while maintaining their rigidity, sustainability and uniformity of deployment. The comparison of the finite-element models of the deployment of thin-walled metal shells having equal initial geometry and thickness at a different number of folds and compactness has been performed. The full-scale experiment to deploy similar shells and compare the kinetics of the deploying process with the results of the numerical experiment was conducted. The interconnection of the geometric accuracy of the unfolding of multisectional deployable structures of the conical type with their compactness, and elastoplastic properties of the material of the metal shell has been investigated. The paper presents the results of the performed experimental studies of tightness conditions of the metal shell related to the quality, plasticity and strength of its welded joints.