Patent ID: 8511957
Filing Date: 2013-08-20
Classification: F16B

Abstract:
1. A self-tapping fastener for forming threads within a substrate, comprising: a head portion; an axially oppositely disposed forward end tip portion; a shank portion extending from said head portion to said forward end tip portion; at least one self-tapping thread lead defined upon said shank portion for forming female threads within a substrate, wherein said at least one thread lead comprises a plurality of successive threads axially spaced from each other by means of a predetermined pitch; and a pair of flats formed upon diametrically opposed external surface portions of said shank portion of said self-tapping fastener for defining discontinuous portions within said at least one thread lead, wherein said pair of flats extend axially rearwardly from said forward end tip portion of said shank portion of said fastener so as to effectively intercept at least two of said plurality of threads, wherein said discontinuous portions of said at least one thread lead circumferentially overlap said pair of flats so as to define transition regions from said pair of flats to said at least one thread lead in order to define cutting edge portions upon said at least one thread lead as well as undercut portions located between each of said cutting edge portions and said pair of flats, wherein said pair of flats provide for the escape of debris generated during thread-cutting operations, wherein said circumferentially overlapped transition regions of said plurality of threads have semi-circular cross-sectional configurations so as to define cutting edge portions which will provide said cutting edge portions with reduced torque levels for optimizing the self-tapping threading of said fastener within a substrate, and wherein, in light of the interception of said pair of flats with at least two of said plurality of threads, at least four cutting edge portions of said self-tapping threads, comprising two pairs of diametrically opposite self-tapping threads, are formed upon said fastener so as to effectively provide built-in redundancy for preserving said self-tapping properties of said plurality of threads.