Abstract: A screwdriver has an undercut enlarged foot portion and an anti-shift pivot element of one-piece therewith. The screwdriver is longitudinally inserted into a screw such that the foot portion and the pivot element are respectively received with clearance in an undercut slot and a central cavity formed in the screw head. Rotation of the screwdriver about the pivot element causes the foot portion to slide partially underneath and grippingly engage the side walls of the slot. A screwholding attachment is adjustable in fine, continuous manner relative to the screwdriver.