A blind fastener device for fastening at least two workpieces, including a sleeve, an expander having a tensioning section, a locking section, and an expansion section, and a nut. A portion of the expander passes through the sleeve to cooperate with the nut so that relative rotation of the expander and nut draws the expander's distal end toward the sleeve's proximal end thereby drawing a portion of the expansion section of the expander into a structural region located on the sleeve and expanding at least a portion of the sleeve's structural region, and drawing a portion of the locking section past the sleeve's distal end toward the sleeve's proximal end and deforming at least a portion of the sleeve's distal end to a locked state.