Abstract: A method for holding a spindle of a mobile power tool in order to allow an opening and/or a closing of a tool fitting by turning an operating part of the tool fitting relative to the spindle, where the spindle is rotationally coupled to an electric motor. The method includes detecting a rotation of the spindle and/or of the electric motor in a first direction while a setpoint angular velocity is zero and controlling the electric motor to generate a torque in a second direction which is opposite to the first direction.

Abstract: The invention relates to a method for operating a hand-held machine tool with a tangential impact mechanism which can be driven by means of a drive shaft and an electric motor, according to which method an actual torque provided by the drive shaft is adjusted to a required torque depending on a measured motor current, wherein the required torque is less than a triggering torque of the tangential impact mechanism.

Abstract: The invention relates to a method for operating a hand-held machine tool with a tangential impact mechanism which can be driven by means of a drive shaft and an electric motor, according to which method an actual torque provided by the drive shaft is adjusted to a required torque depending on a measured motor current, wherein the required torque is less than a triggering torque of the tangential impact mechanism.

Abstract: A drill, which is used in a hammer drill for drilling holes in stone, concrete and the like, includes a one-piece drilling head (10, 20, 30) formed of a hard material and provided, at its first end (5), with at least one main bit having a tip (4) and at least one cutting structure (3) integral to the one-piece drilling head (10; 20; 30), and at a second end (6) located opposite the first end (5), with a bottom surface (7) for the mounting the drilling head (10; 20; 30) on the drill stem (8), and having a plurality of axially extending through-grooves (11; 21; 31) for removing drillings produced during a drilling process and having a cross-section which increases, at least regionwise, in a direction toward the bottom surface (7) of the drilling head (10; 20; 30).

Abstract: A drill, which is used in a hammer drill for drilling holes in stone, concrete and the like, includes a drilling head (10, 20, 30) formed of a hard material and provided, at its first end (5) with at least one main bit (3) having a tip (4), and at a second end (6) located opposite the first end (5), with a bottom surface (7) for the mounting the drilling head (10; 20; 30) on the drill stem (8), and having a plurality of axially extending through-grooves (11; 21; 31) for removing drillings produced during a drilling process and having a cross-section which increases, at least regionwise, in a direction toward the bottom surface (7) of the drilling head (10; 20; 30).