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 building structure including a first building member and a second building member may be connected by a plurality of fasteners, each fastener having a head, a threaded portion having a through hardness of between HRB 70 and HRC 40, a thread-forming portion of at least HRC 50 hardness enabling the fastener to form threads in at least the second steel building member, and a fluted lead portion of at least HRC 50 hardness with a nominal diameter between 70 and 95% of major diameter, such that the fastener is capable of providing a ratio of strip torque to thread-forming torque of at least 3.0 and a ratio of strip torque to drive torque greater than 6.0 when the second steel building member having a thickness of 0.25 inch and the fluted lead portion having at least one diameter within nominal diameter between 80 and 98% of major diameter.