New Blind, Doweling, Temporary Fastener Design and Testing

Several new families of expanding mandrel type of temporary (slave) fastener are in production and/or undergoing qualification tests. These fasteners are characterized by a collapsible mandrel that expands when needed over a center spindle. These fasteners are blind (installed and removed from one side only), and they provide locating (dowel) capabilities. This paper illustrates how these new fasteners work and how they are designed. Results of some testing of nominal ¼″, flush head fasteners in carbon-fiber reinforced plastic are shown. Design criteria include the temporary fasteners clamping ability, acceptable contact stresses, cyclic fatigue life, and strength.