Abstract: Apparatus is disclosed for supplying and installing plastic expansion rivets with breakaway mandrels in holes in a workpiece. It comprises a hand-held, trigger actuated, pneumatically-operated installation tool; a rivet-supply mechanism for supply rivets one-by-one to the tool on a timely basis; and a vacuum-operated, mandrel-removal mechanism for removing broken away mandrels from the tool. The installation tool has a hollow barrel with a nose piece at its working end for receiving and releasably holding each rivet delivered thereto. Two piston assemblies are slidably mounted in the hollow barrel: one maintains the rivet body stationary against the workpiece and the other has jaws thereon for gripping and pulling on the rivet mandrel to expand the rivet body and break away the mandrel. The hollow barrel also contains a vacuum tube through which broken-away mandrels are expelled.