Sheet screw with screw head - comprising cylindrical screw shaft with threaded screw point section that has two linked conical sections that ends in screw point

摘要

The sheet screw comprises a screw head which is in a cylindrical screw shaft (1) that has a thread (2), which ends in a screw point (4), stemming from a screw point section (3), that is in conical form with a point angle of between 55 and 60 degrees. The screw thread continues up to the screw point. A second obtuse conical section (7) may be linked to the conical form section (5) whose end is the screw point. The point angle may be as small as that of the first region. The point angle of the second conical section, of the screw point section, may be between 18 and 22 degrees. The length, between the first conical section and the screw point, may be two-thirds the length, between the screw point section and the screw point.