A threaded screw fastener is provided with a head portion that has integrally incorporated therein dual drive structure whereby the single threaded screw fastener can be rotatably driven by alternative rotary drive socket implements or tools, such as, for example, hexagonally configured or Phillips head...http://www.google.es/patents/US7207248?utm_source=gb-gplus-sharePatente US7207248 - Threaded screw fastener characterized by high pull-out resistance, reduced installation torque, and unique head structure and drive socket implement or tool therefor
Threaded screw fastener characterized by high pull-out resistance, reduced ...
