Screw for mechanical fixing of insulating and sealing material on flat roof, has screw head, in which drive bed for inner drive is inserted for receiving screw bit, where vertex of head possesses flattening, on which plane surface is formed
摘要
<p>The screw (1) has a shaft (2) with a screw thread and a screw head (3), in which a drive bed (7) for an inner drive is inserted for receiving a screw bit, where the drive bed is a cross slot bed. The screw head is designed as a round head. A vertex of the screw head possesses a flattening (9), where a plane surface is formed on the flattening. The plane surface is directed orthogonal to a screw longitudinal axis.</p>
