Screwdriver for tightening screws comprises ribs becoming narrower in the radial direction and wider in the peripheral direction with increasing distance from the end surface of the working end

摘要

Screwdriver (1) comprises a working end (3) having ribs (R) running in an axial direction and directed radially outward away from a truncated core (K) to form grooves (N). The limit lines (7) of the groove bases (8) run parallel to each other so that with increasing distance from the end surface (9) of the working end the ribs become narrower in the radial direction and wider in the peripheral direction. Preferred Features: The cross-section lines passing through the groove bases lie on circles around the center (X) of the screwdriver and the radius becomes greater with increasing distance from the end surface.