Abstract: Coupling device (1) for a pipe (2), including a sleeve (13) for receiving the pipe (2) and at least one sealing member (5) to provide a seal between the sleeve (13) and the pipe (2), a pressure member (6) for applying a pressure to the sleeve (13) and to the pipe (2), and a grip element (4) extending along at least a part of the perimeter of the pipe (2), wherein the grip element (4) is provided with dents (9) pressed out of the plane of the grip element (4) adjacent to slit like openings (8) punched out of the grip element (4), wherein edges (8?) of the slit like openings (8) are subjected to a peening operation.

Abstract: The invention provides a method for machining a shape such as slot or cavity or aperture using a plurality of first type holes (1) and second type holes (2), wherein during machining of first type holes (1) the hole circumference completely envelopes the respective portion of the electrode circumference.