System for connecting juxtapposed sectional boards

A system connecting sectional boards, particularly panel-like elements having rectangular greater surfaces and horizontal greater sides to form partition walls, wherein the system comprises two metal section connecting a lower section board to an upper sectional board, one metal section being attached to the upper greater horizontal side of the lower sectional board and the other metal section being attached to the lower greater horizontal side of the upper sectional board, said metal sections being connected to each other by means of a tongue-and-groove joint and forming, one they are connected together, a recessed portion extending along the greater horizontal side of the sectional boards and intended to receive and hold therein a corresponding portion of an element or fixture intended to project or to hang from the partition wall, wherein the metal sections contact the associated sectional boards through contact surfaces having a flat and horizontal rear portion and a flat and slant front portion terminating with a lip.