| 摘要 |
<p>A cap screw has an essentially cylindrical, cup-shaped socket head (5) intended for an internal drive with axial, diametrically opposite driving ribs (8, 9) projecting inward from the wall (7). A central, axial centering pin (13) provided with a diametral slot (14) in alignment with axial recesses (10, 11) in the driving ribs (8, 9) projects from the socket head (5) above the rim (23) of the cap screw.</p> |
