A rivet for fastening workpiece members, the rivet including a body comprising a shank extending in a first, longitudinal direction and a head extending in a second, substantially transversal direction, a bore being defined through the shank and the head of the body; and, a stem comprising a main longitudinal portion arranged for insertion into said bore, and an enlarged portion arranged for radially expanding the shank when the enlarged portion is forced into said bore to fasten the workpiece members; the rivet being configured for insertion into respective apertures formed in the workpiece members; and the rivet being further configured such that when the workpiece members are fastened, the head of the body of the rivet is displaced relative to the shank to engage with the stem to lock the stem in place relative to the body and/or the workpiece members.