Abstract: In a part having a rotationally symmetric region and a machining surface, and a method for manufacturing the part from a blank, the machining surface is finished in a planar manner. The normal direction of the machining surface is oriented parallelly to the axis of symmetry, e.g., an axis of rotation, of the rotationally symmetric region. The part includes an annular groove that extends around in a circumferential direction, e.g., with respect to the axis of symmetry. In a circumferential angular region covered by the machining surface, the annular groove is incomplete, e.g., removed down to the groove base of the annular groove, and in a circumferential angular region not covered by the machining surface, the annular groove is complete, e.g., the machining surface bordering on the annular groove and/or leading into the annular groove.