Screw especially for venting a braking system of a vehicle

The screw i.e. bleeder screw (2), has an internal space (16) closed at one end and opened at another end of the screw. A duct traverses a wall of the screw and emerges into the internal space of the screw. The duct is formed by a radial bore (15) in the wall of the screw through a forging operation without detachment of material of the wall of the screw. The bore is located between a truncated cone-shaped sealing head (13) of an internal end part of the screw and a thread (7) of a cylindrical hollow body of the screw.