Patent ID: 6142719
Filing Date: 2000-11-07
Classification: F16B

Abstract:
A self-drilling screw, comprising a head (3; 6), a thread section (2, 5) adjoining the head (3; 6), and a drilling section (1; 4) adjoining the thread section (2; 5) and formed of first (11; 41) and second (12; 42) parts arranged one after another, the drilling section (1; 4) having first and second cutting edges (15, 16; 45, 46) and two, diametrically opposite, first and second discharge grooves (13, 14; 43, 44) extending parallel to a longitudinal axis of the screw at least along a portion of a longitudinal extent of the drilling section (1; 4) and associated with the second and first cutting edges (15, 16; 45, 46), respectively,wherein a radial extension of the cutting edges (15, 16; 45, 46) is symmetrical with respect to the longitudinal axis of the screw in the first, in a drilling direction, part (11, 41) of the drilling section (1; 4),wherein at least a portion of the second part (12, 42) of the drilling section (1, 4), which is located between the first part (11, 41) and the thread section (2; 5), has, in a region of the second discharge groove (14, 44), a radial extension (R1; R3) less than a half of a root diameter (D1; D3) of the thread section (2; 5), andwherein the second part (12, 42) of the drilling section (1, 4), has, in a region of the first discharge groove (13; 43) a radial extension (R2; R4) which is smaller than a half of the pitch diameter (D2; D4) of the thread section (2, 5) and is greater than the half of the root diameter (D1, D3) of the thread section (2; 5).