Abstract: The invention relates to a motor-driven hand tool for machining of workpieces, in particular planar workpieces, having a guide surface which can be placed on the workpiece to be treated, and a face milling cutter for processing which projects past the guide surface, and which has an axis of rotation extending perpendicularly to the guide surface.

Abstract: A hammer drill has clamping jaws which are provided, in addition to clamping surfaces for radial clamping a cylindrical tool shaft, also with additional axially extending guiding surfaces for axially non-rotatably holding and guiding of the tool shaft, and the tool shaft is provided with guiding grooves associated with the clamping jaws.

Abstract: A chuck for hammerdrills and the like is provided with a chuck body; a plurality of jaws on said chuck body for engaging and holding a tool bit; and means connected to said jaws for adjusting the engagement of said jaws with the tool bit, said means comprising a guide sleeve having a main portion with an outer and inner surface, said main portion defining a central axis therethrough, a toothed gear encircled by said sleeve and having a circumferentially extending groove having a roughened surface facing the inner surface of said sleeve, said sleeve including at least one inwardly offset locking portion having an outer and inner surface which are inwardly offset with respect to the main portion of said sleeve, said inwardly offset portion projecting into said groove.