Abstract: A method is provided for rotationally attaching a connection fitting with an opposing surface by screwing the fitting into the opposing surface by threads on an outer surface of the fitting body. The connection fitting is formed by at least one seal manufactured together with the fitting body in an injection molding process to form a multi-component plastic part in which the fitting body is made of a hard plastic component and the seal is made of a soft plastic component, wherein the components are of a kind which do not adhere to one another. The seal is secured in an axial direction on the fitting body in a form-fit manner, but during the rotational attachment step the seal is rotatable relative to the fitting body in a peripheral direction.

Abstract: A connection fitting (1), for example a blind plug, valve body, pipe connection piece or the like, with a fitting body (2, 8) and a seal (4) has the form of a multi-component plastic part, in which the two plastic components are plastics that are incompatible with each other, so that the seal (4) can rotate relative to the fitting body (2), in particular when the seal contacts an uneven or fissured opposing surface by which it could be damaged if it continued to be turned when tightening or screwing in the connection fitting (1) relative to this opposing surface.