A self-drilling screw including a drilling section (1; 4) adjoining a thread section (2; 5) of the screw and formed of first (11; 41) and second (12; 42) parts arranged one after another, within the drilling section (1; 4) having first and second cutting edges (15, 16; 45, 46) a radial extension of which...http://www.google.de/patents/US6142719?utm_source=gb-gplus-sharePatent US6142719 - Self-drilling screw
