Abstract: In a fastener having a head, which may have having torque-absorbing ribs, and a shank, which is unitary with the head and which has a primary thread formation and a secondary thread formation. The primary thread formation, which defines axially spaced threads along a generally cylindrical portion of the shank and along a tapered tip of the shank, has a generally uniform radial dimension along the generally cylindrical portion of the shank. The secondary thread formation, which defines axially spaced threads between some of the threads defined by the primary thread formation, originates at a region spaced axially from the distal end of the generally cylindrical portion of the shank, terminates at the head, and tapers outwardly from the region where it originates toward the head. The secondary thread formation at the region adjoining the head has a radial dimension less than the generally uniform radial dimension of the primary thread formation along the generally cylindrical portion of the shank.

Abstract: A faying plate having a clearance hole is fastened to a tapping plate having a tapping hole by a fastener having a shank with a tapered tip and with a self-tapping thread. The shank, which defines an axis, is adapted to tap a complementary thread around the tapping hole, via the self-tapping thread, when the fastener is driven rotatably. The fastener has a unitary head with a bearing portion having a peripheral edge and a having surface facing the shank, flaring outwardly toward the shank, and frusto-conical at a conical angle of about 5.degree. relative to a plane perpendicular to the axis. Eight torque-absorbing ribs project from the clamping surface, are spaced at regular intervals about the axis, and have ridges that lie on an imaginary, frusto-conical surface flaring outwardly toward the shank at a conical angle of about 1.degree. relative to a plane perpendicular to the axis and at a conical angle of about 4.degree. relative to the clamping surface. Each rib has a depth from not less than 0.

Abstract: A torque-absorbing rotary threaded fastener for joining metal panels has a stripping torque sufficiently in excess of its driving torque to ensure that it will be relatively unlikely to be stripped when mechanically driven home. The fastener has a clamping face which includes a number of polyhedral nibs extending axially therefrom and separated from one another by substantially planar uninterrupted portions of the clamping face. The nibs include a leading wall and a trailing wall, facing in the direction of tightening and opposite thereto, respectively. The leading wall may be inclined at a steeper angle with respect to the plane of the clamping face than is the trailing wall, or vice versa. The leading wall and the trailing wall meet to form an apex which is also inclined with respect to the plane of the clamping face, so that the nibs increase in axial height as one views outward toward the periphery of the clamping face.

Abstract: A screw for soft material having an assymetrical thread form which includes an upper flank comprised of a plurality of continuous helical surfaces. The upper flank surfaces are configured such that a helical protrusion is formed on the upper flank which causes increased friction between the screw and the workpiece only after seating of the screw head has occurred.

Abstract: A thread forming screw made from a blank which has a tip with an assymetrical cross-section comprised of two oppositely disposed inner surfaces which gradually merge with two oppositely disposed outer surfaces. The inner surfaces may be arcuate or generally flat or a combination thereof. The inner and outer surfaces are generally parallel to each other and to the axis of the screw so that, when rolled, the tip has generally fully formed sharp crested threads which gradually deform workpiece material upon insertion and axially advancing rotation in a bore. The reduced frictional contact is achieved because of substantial unthreaded portions on the inner surfaces. Improved gripping action results from the formation of full threads which extend substantially the full length of the fastener.

Abstract: A rotary fastener is disclosed for use in attaching the first panel to a second panel. The fastener has a head and a shank, which shank has at least one helical thread thereon. Additionally, there is at least one helical ramp extending along the shank from the underside of the head. The underside of the head has a generally annular recess which may have helical ribs therein. The fastener is dimensioned so that as it is driven into the two panels, material of the two panels is drawn up into the recess and binds on the helical ramp along the shank. Additionally, a plurality of nibs located on the underside of the head and extending into the recess "rake" up material as the underside of the head encounters the top panel, which raked material is also drawn into the recess and binds on the helical ramp. This combined binding action by panel material and raked material significantly increases stripping torque of the fastener during installation.

Abstract: A rotary fastener for use in attaching sheet metal or attaching articles to sheet metal. The fastener has a serrated helical ramp forged in the undersurface of the head during the heading operation. The serrations have generally radially oriented surfaces which engage workpiece material to increase strip torque, removal torque or both. The ramp advances helically in an axial direction and the ramp is spiral in cross-section.

Abstract: A screw adapted for use with thin sheet metal. The screw has a threaded shank and a head with an integral flange. The flange has both radial and axial undulations which increase the amount of torque required to strip the screw. The undulations are formed at the outer edge of the flange and on the under surface of the flange and are adapted to engage a workpiece upon threaded advancement of the screw.

Abstract: A fastener assembly for attaching articles to a penetrable surface such as drywall material found in the interiors of buildings. The assembly is comprised of a fastener, which fastener has a threaded shank with a pointed end and either a head or a second threaded end and an anchor member piercedly captured by the threaded shank of the fastener. The anchor member is held in a position substantially parallel to the axis of the threaded shank with the pointed end extending beyond the anchor member by a retaining means while the assembly is piercing a surface; as the assembly pierces the surface, the retaining means slips from engagement with the anchor member and, as the anchor member passes through the rear side of the surface penetrated, spring means on the anchor member urge the anchor member to a position substantially oblique to the axis of the threaded fastener.

Abstract: A self-penetrating fastener assembly for anchoring in wallboard has a pointed anchor member and a threaded fastener. The anchor member has a longitudinal recess formed by semicylindrical segments which intersects an aperture that extends through the anchor. The fastener is aligned within the recess which engages the threads of the fastener, the head thereof protruding beyond the end of the anchor and the assembly is hammered into the wallboard. When the anchor clears the wallboard, the fastener is threadingly advanced into the anchor which, in turn, is drawn up against the back of the wallboard securely attaching an article thereto.

Abstract: An integral stud member having shank portions extending from either side of a radially extending flange. A first shank portion including thread convolutions with means to form mating internal threads in an associated workpiece. The surface of the flange opposing the first shank including generally radially extending rib-like surfaces which serve as the means to drive the fastener in place. The rib structures are configured to permit a driver to softly engage the flange and to lock the fastener from backing out of the workpiece after a secondary work surface has been clamped over the flange.

Abstract: An improved terminal clamp assembly adapted for removably securing and electrically connecting a pair of conductor wires. A plate element of the clamp assembly is preassembled to a fastener having a threaded shank and clamping head with the plate configured so as to tilt relative to the axis of the fastener permitting the interconnection of two conductors having different diameters. A plurality of ribs, including alternately disposed sets, are formed beneath the clamping surface of the plate with each set of ribs tapering in different directions to create a plurality of laterally directed forces on a single conductor wire in different and opposing directions.