The present invention refers to a group of elements for the realization of joints connecting and tightening two or more variously reciprocally oriented or orientable sections, whether tables, axes, laths, tubes or the like, variously oriented and orientable through the overlying association of at least two bodies, with coupling surfaces shaped to correspond to the surfaces of said sections to be joined, reciprocally fixed by at least one fixing and axial joint means, orthogonal to the directions in which each pair of sections is oriented; said joint means comprising two parts, associated respectively with said two bodies, complementarily fixable by means of a common bolt and allowing a continuous variability of the reciprocal angles between said bodies and a preestablished number of rigid angles between them, and so between the sections connected to them.