Abstract: A method for producing a media-tight material composite, in particular comprising a metal solid body and an optionally electrically insulating plastic at least partially surrounding the solid body, preferably as a component of a preferably shielded electrical interface, wherein surfaces of the solid body that the plastic contacts are subjected to a surface pretreatment in order to promote the adhesion of the plastic to the solid body. The disclosure further relates to a cylindrical metal sleeve, in particular as part of a plug connector, and a plug connector or sensory comprising a metal sleeve, produced by the foregoing method.