Abstract: The coupling arrangement according to the invention is universally used for modular tool-systems and its simple construction allows economic production. The threaded bore of one of the elements to be engaged is provided with thread identical with that of the other element, and differential screw is screwed into these threads, furthermore the driving element is such driving pin one half of which is fitted into the parallel and excentric bore of one of the elements, while the diameter of the other half is smaller, its end excentrically arranged in relation to the former half is provided with a conical end section and fitted into the bore of the other element.