Ldquopoprdquo or blind rivets are manufactured from aluminium with a central steel mandrel the rivet mandrel is placed in the nose piece of the riveting tool and the rivet body is then inserted in the pre drilled hole in the work piece to be assembled the riveting tool is then operated which pulls the mandrel head into the body of the rivet so forcing it to form a head around the mandrel end when the rivet head has been fully formed and the assembly firmly drawn together the mandrel b