An RF plug connector having a plug head on which a sliding sleeve is seated which can be rotated, can be moved axially and clasps a radially elastic collet (4) in such a manner that the sliding sleeve compresses the collet radially in the coupled state, the design can be considerably simplified in comparison to that of known plug connectors of this generic type, to be precise by the collet (4) being arranged such that it cannot be moved axially on the plug head. For connection to a coupler with an external thread, the collet (4) has internal profiling on the plug side, in particular an internal thread with a pitch which is not the same as that of the external thread of the coupler.