Abstract: A thread forming screw thread fastener and a corresponding thread roll die are disclosed for fastening into a hole of a workpiece composed of low ductility material. More specifically, the thread forming screw thread has smooth radius thread flank which has a capability of deforming low ductile material such as magnesium, soft aluminum, thermoset plastics and other low ductility materials to deform the ductile material efficiently minimizing cracks, debris, low friction during installation and a maximum engagement of the screw with mating parts with the ductile material.

Abstract: A thread forming screw thread fastener for fastening into a hole formed by the fastener in a work piece, the fastener comprising: a head having a drive to be engaged with a driver bit; and a shank with threads having a symmetrical thread profile with a minor diameter and a major diameter, the major diameter defining a thread crest of the screw thread, and the minor diameter defining the thread root of the screw thread, the profile of the screw thread defined by the surface of the screw thread between adjacent thread crests forming a thread flank, the thread flank having a first central portion of constant radius along the thread root, the radius common at the thread root, at each adjacent thread crests, and at two transition intersection points, the profile of the thread flank having second and third portions defined by surfaces having different radii of curvature between each transition intersection point and each adjacent thread crest.

Abstract: A thread forming screw thread fastener and a corresponding thread roll die are disclosed for fastening into a hole of a workpiece composed of low ductility material. More specifically, the thread forming screw thread has smooth radius thread flank which has a capability of deforming low ductile material such as magnesium, soft aluminum, thermoset plastics and other low ductility materials to deform the ductile material efficiently minimizing cracks, debris, low friction during installation and a maximum engagement of the screw with mating parts with the ductile material.

Abstract: A fastener with a recess head wherein the drive head has four lobular recess channels. Each channel comprises a first wall, a second wall, a bottom surface and a recess sidewall. The first and second walls have portions opposing each other and a constant radius of curvature to form a continuously and smoothly forming wall of the channel. A torque producing driver tool is defined with cross sectional signature substantially complementary in size and shape of the recess of the drive head of the fastener for matable engagement. A recess punch for manufacturing the fastener is also defined and comprises a punch holder and a punch pin integral with the holder.