A self-plugging blind rivet 10 comprises a tubular body 14 having a preformed head 34 at one end, and in the bore 36 of which a headed stem 12 is disposed. The stem 12 projects from the head 34 end of the body 14, and the head 18 of the stem 12 is substantially enclosed by a region 42 of the body 14 remote from the preformed head 34. The head 18 of the stem 12 abuts a shoulder 44 provided by a region 43 of the body 14 in which the diameter of the bore 36 is reduced and the wall is thickened. Axially spaced apart annular grooves 46, 48 in the external surface of the body 14 define between them a portion 50 which will collapse to form a blind head when the body 14 is compressed axially by pulling the stem 12 while supporting the preformed head 34. Finally, the stem head 18 may be pulled into the reduced diameter region 40 of the bore 36 and thereby cause the blind head to be reshaped and forced into compressive engagement with work being fastened. The stem head 18 remains securely enclosed by the body 14, whereby its loss is prevented.