An apparatus for clamping a component on a rotating machine part, in particular a balancing machine, having a basic body, having a clamping mandrel, which is arranged in an axially displaceable manner within the basic body, and having a plurality of clamping devices, which can be moved between a release position and a clamping position by axial displacement of the clamping mandrel. In order to make it possible for components to be clamped centrally with repeated accuracy, the clamping devices are designed as clamping segments which can be displaced radially in relation to the center axis of the basic body above the latter.

The invention relates to a machine (1) for machining pipe ends. At least one centering device (8; 35) is associated to said machine, which centering device centers a tubular workpiece (5, 5) in relation to an axis of rotation (D) of the machine for machining pipe ends extending in the center of the machine, the tubular workpiece either being stationary in the case of a rotating tool head (4) or rotating in the case in which the tubular workpiece is fastened in the machine chuck (9). Precise centering of the tubular workpiece (5, 5) is quickly and simply achieved in that the centering device (8; 35) has a clamping housing (13; 130) that is open toward the axis of rotation (D), which clamping housing is designed comprising at least three means (14, 15, 16; 140, 150, 160) for contacting the tubular workpiece at the outer circumference and for clamping the tubular workpiece (5, 5) in a centered manner, which means are circumferentially distributed and adjust mechanically independently of each other to the particular diameter of the workpiece (5, 5) to be machined.

A gripping device (100) for holding, centring and/or clamping a micromechanical or horological component (200) in a chamber delimited by a collet including at least one movable jaw (2) and at least one stationary jaw (3), wherein some of the movable jaws (2) and/or stationary jaws (3) include a reference surface (20) to support a component (200) bearing frontally thereagainst, and the gripping device (100) includes both, on the one hand, stationary jaws (3) including the reference surface (20) to support the component (200) bearing thereagainst, and movable jaws (2) for centring and/or clamping the component (200), and on the other hand a vacuum generator (60) for creating the vacuum in the clamping chamber. Also a related method.