Abstract: A self-clinching fastener suitable for connection to a member having a shank of a diameter less than a head portion, the head portion having at least eight lands extending outwardly along the underside of the head portion spaced about the shank, each land having a face surface extending beyond the shank to a diameter less than or equal to the radius of the head portion, the width of the lands reducing from adjacent the shank toward the radius of the head portion. The fastener further includes an axial annular engagement groove having a diameter larger than the shank, the annular engagement groove axially extending from the lands to a retaining collar adjacent the shank, the groove adapted to relieve material of a member on installation by receiving material as the lands in the underside of the head portion mechanically interlock with the member.

Abstract: A self-clinching fastener suitable for connection to a member having a shank of a diameter less than a head portion, the head portion having at least eight lands extending outwardly along the underside of the head portion spaced about the shank, each land having a face surface extending beyond the shank to a diameter less than or equal to the radius of the head portion, the width of the lands reducing from adjacent the shank toward the radius of the head portion. The fastener further includes an axial annular engagement groove having a diameter larger than the shank, the annular engagement groove axially extending from the lands to a retaining collar adjacent the shank, the groove adapted to relieve material of a member on installation by receiving material as the lands in the underside of the head portion mechanically interlock with the member.

Abstract: A self-clinching fastener suitable for connection to a member having a shank of a diameter less than a head portion, the head portion having at least eight lands extending outwardly along the underside of the head portion spaced about the shank, each land having a face surface extending beyond the shank to a diameter less than or equal to the radius of the head portion, the width of the lands reducing from adjacent the shank toward the radius of the head portion. The fastener further includes an axial annular engagement groove having a diameter larger than the shank, the annular engagement groove axially extending from the lands to a retaining collar adjacent the shank, the groove adapted to relieve material of a member on installation by receiving material as the lands in the underside of the head portion mechanically interlock with the member.

Abstract: A thread forming fastener for use in concrete, masonry, brick, and the like, having a first thread, second thread, and third thread about a shank, the second thread having a major diameter greater than the major diameter of at least one of the first and third threads with grooves on either side of the second thread adapted to accommodate chips of material during fastening, and the second thread having notches in the major diameter of at least one turn adapted to engage at least one of concrete, masonry, and brick, a helical land axially extending between the third thread and adjacent first thread having an outside diameter greater than the minor diameter and less than the major diameter of the first thread and third thread, the axial land width between the third thread and adjacent first thread being at least 25% of the thread pitch.