| 摘要 |
The screw head described has a recess (4) similar to that of a cross-slotted screw head. The recess (4) is intended as the force-application zone for a screwdriver. To this purpose, the recess (4) has slots (6) extending radially outwards. The flanks (7) of the slots form the surfaces on which the screwdriver torque is applied. The inner edges (9) which form the transition, in the direction (22) round the screw head, between the slot flanks (7) and the sector-shaped peripheral surfaces (8) in the centre of the recess between the slots (6) are straight lines. They each lie in an imaginary plane (10) containing the screw axis (3) and extending out radially from the axis. In addition, these edges converge in the direction away from the end surface (5) of the screw head to intersect at a point P on the screw axis (3). |
