A reamer screw having an elongated shank, with a leading end and a trailing end, at opposite ends, and having a self-tapping/cutting threaded portion at the leading end adapted for self-tapping and cutting an opening through a workpiece, and driving securely into a substrate, a torque formation at the...http://www.google.es/patents/US5987837?utm_source=gb-gplus-sharePatente US5987837 - Reamer screw and building panels erected with reamer screws
Reamer screw and building panels erected with reamer screws
