Fastener

A fastening element, comprising:

• a gripping portion having a first face and a second face, the first face of the gripping portion comprising a plurality of gripping elements;
• a supporting portion being defined by at least two supporting-portion walls extending from the gripping portion in a direction opposite that of the gripping elements, the supporting portion having a supporting-portion width smaller than a gripping-portion width of the gripping portion, such that a top flange is formed by the gripping portion relative to the supporting portion on at least one side of the fastening element;
• and
• an anchoring portion extending from a distal end of at least one supporting-portion wall and parallel to the gripping portion thereby defining a bottom flange relative to the supporting portion on the at least one side corresponding to the top flange,
• wherein the bottom flange comprises at least one chamfer located at a terminal section of the bottom flange.