<p>The screw has a spherical section (22), which connects the pointed-conical section (21) toward the head (14) and whose lateral surface (12) has a radius of curvature (R1) in axial direction. The other spherical section (24) is arranged between the spherical section (22) and the cylindrical section and whose lateral surface (16) has other radius of curvature (R2) in axial direction. The former radius of curvature (R1) is unequal to the latter radius of curvature (R2).</p>
