Abstract: A fastening element (20) is provided for use with a tightening element (14) in a device for forming a joint between two panels (18,22). The fastening element is elongate and has a head (13) at one end for engaging the tightening element, an expander (15) at the other end and a shank (11) extending there between. The fastening element further comprises a sleeve (10) having an expandable section (16) at one end extending over the expander, with the expander operatively engaging the sleeve to cause outward movement of its expandable section upon axial displacement of the fastening element relative to the sleeve. The sleeve is provided with at least one outwardly facing cutting edge (19) on its expandable section. The cutting edge has sufficient strength to cut into the panel material in use of the device, when the expandable section is inserted into a face hole in a first one of the panels.

Abstract: A fastening element (20) is provided for use with a tightening element (14) in a device for forming a joint between two panels (18,22). The fastening element is elongate and has a head (13) at one end for engaging the tightening element, an expander (15) at the other end and a shank (11) extending there between. The fastening element further comprises a sleeve (10) having an expandable section (16) at one end extending over the expander, with the expander operatively engaging the sleeve to cause outward movement of its expandable section upon axial displacement of the fastening element relative to the sleeve. The sleeve is provided with at least one outwardly facing cutting edge (19) on its expandable section. The cutting edge has sufficient strength to cut into the panel material in use of the device, when the expandable section is inserted into a face hole in a first one of the panels.