Abstract: A self-clinching fastener for attachment to a plastically deformable metal panel includes a body portion with a central axis and a central pilot portion extending from the body portion and coaxial with the central axis. The body portion forms a generally annular-shaped end face adjacent the central pilot portion and a groove defined in the end face encircling the central pilot portion. The groove has an inclined inner wall forming an undercut and an inwardly inclined bottom wall such that the groove has an increasing depth in a direction toward the undercut. The inclined bottom wall is formed by a plurality of generally flat faces and the inclined inner wall is formed by a plurality of generally flat faces which are aligned with the faces of the bottom wall. The fastener further includes a plurality of spaced apart lugs encircling the central pilot portion and axially extending from at least one of the end face and the groove. The lugs form abutments to improve torsional resistance of the fastener.

Abstract: A self-clinching fastener for attachment to a plastically deformable metal panel includes a body portion with a central axis and a central pilot portion extending from the body portion and coaxial with the central axis. The body portion forms a generally annular-shaped end face adjacent the central pilot portion and a groove defined in the end face encircling the central pilot portion. The groove has an inclined inner wall forming an undercut and an inwardly inclined bottom wall such that the groove has an increasing depth in a direction toward the undercut. The inclined bottom wall is formed by a plurality of generally flat faces and the inclined inner wall is formed by a plurality of generally flat faces which are aligned with the faces of the bottom wall. The fastener further includes a plurality of spaced apart lugs encircling the central. pilot portion and axially extending from at least one of the end face and the groove. The lugs form abutments to improve torsional resistance of the fastener.

Abstract: A self-clinching fastener for attachment to a plastically deformable metal panel includes a body portion with a central axis and a central pilot portion extending from the body portion and coaxial with the central axis. The body portion forms a generally annular-shaped end face adjacent the central pilot portion and a groove defined in the end face encircling the central pilot portion. The groove has an inclined inner wall forming an undercut and an inwardly inclined bottom wall such that the groove has an increasing depth in a direction toward the undercut. The inclined bottom wall is formed by a plurality of generally flat faces and the inclined inner wall is formed by a plurality of generally flat faces which are aligned with the faces of the bottom wall. The fastener further includes a plurality of spaced apart lugs encircling the central pilot portion and axially extending from at least one of the end face and the groove. The lugs form abutments to improve torsional resistance of the fastener.

Abstract: A self-clinching fastener for attachment to a plastically deformable metal panel includes a body portion with a central axis and a central pilot portion extending from the body portion and coaxial with the central axis. The body portion forms a generally annular-shaped end face adjacent the central pilot portion and a groove defined in the end face encircling the central pilot portion. The groove has an inclined inner wall forming an undercut and an inwardly inclined bottom wall such that the groove has an increasing depth in a direction toward the undercut. The inclined bottom wall is formed by a plurality of generally flat faces and the inclined inner wall is formed by a plurality of generally flat faces which are aligned with the faces of the bottom wall. The fastener further includes a plurality of spaced apart lugs encircling the central pilot portion and axially extending from at least one of the end face and the groove. The lugs form abutments to improve torsional resistance of the fastener.