| 摘要 |
<p>A system for fixing an accessory (2) on a metal frame (3) for doors, windows, and the like, including a screw (1) having a head (5) and a self-tapping threaded stem (4) with metric thread, the end (8) of which opposite to the head (5) is tapered. The ratio between the external diameter of the self-tapping stem (4) of the screw (1) and the diameter of the through hole (16) of the wall (15) of the frame (3) is comprised approximately between 1.4 and 1.25, and the ratio between the diameter of the through hole (16) of said wall (15) and its thickness is comprised approximately between 2.5 and 5.5 and more preferably between 3 and 5.</p> |
