| 摘要 |
<p>It comprises a head (1) and a threaded shank (2,3), with said shank including a widened zone (21) in contact with the lower face (12) of the head (1), and it is characterized in that the head (1) complies with the ratios: <DF>0.135≤k/dk≤0.21 dc/d1 < 1.1 </DF> where k is the height of the head (1), dk is the diameter of the lower face (12) thereof, dc is the maximum diameter of the widened zone (21) of the shank and d1 is the nominal diameter of the shank thread (3). The screw does not interfere with moving elements which slide over the screw, and it can be fixed in holes of small diameter; further, the transition zone does not warp when profiles of low thickness are joined together. <IMAGE></p> |
