Fastener inserted into work pieces with proper hole size...
The mandrel head slips into the rivet body and presses it against the hole, the counter compressive force on the rivet body results in a deformation and extension of the hollow mandrel head, thus allowing the rivet to adapt itself optimally to all riveting materials and hole characteristics.
The locking collar is forced into the upper locking groove of the mandrel through the pressure of the setting tool nosepiece, thus forming the internal and external lock. At this point the Dual-Locking sequence ist complete and the mandrel breaks flush with the rivet head.