Abstract: A double action blind rivet assembly comprising an outer sleeve member with an annular head flange at one end and having an initial outside diameter such that it is receivable through the holes in the workpieces and a length such that it projects from the blind side of the workpieces for the formation of a blind head therein; an inner sleeve member with an annular head flange at one end and having an outside diameter larger than the inside diameter of the outer sleeve member so that, when the inner sleeve member is driven into the outer sleeve member from the accessible side of the workpieces, it will expand the outer sleeve member into a prescribed interference fit by expanding the holes through the workpieces with the inner sleeve member also having a length such that it projects from the blind side of the workpieces after it is driven into the outer sleeve member; and internally supporting the inner sleeve member while it is being driven into the outer sleeve member with a blind head former section thereon