Self-drilling screw

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), and
• wherein 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).