| 摘要 |
The invention relates to the head of a countersunk screw with a lower side which has at least one supporting surface (2), which forms part of a rotational surface about the screw axis (7) and can nestle against a correspondingly contoured countersunk surface (11) of an add-on part (10), and has at least one depression (6) which is delimited by a cutting edge (4) at its end which runs downwards, as seen in the screwing-in direction (e) of the countersunk screw. The invention is distinguished in that in front of the supporting surface (2), as seen in the screwing-in direction (e), there is an approach surface (3) which butts against said supporting surface, is inclined radially inwards and, at its upwardly running, free end, has the cutting edge (4) which, over its length, maintains a radial distance (a) from the rotational surface to the inside. |
