A device for the forced locking of two elements oriented orthogonally to one another, especially suitable for steadily connecting and constraining two tubular elements with quadrangular or polygonal section which are partly delimited by a U-shaped band and which have, on at least one face, a plurality of pairs of shaped recesses, whereas the band is correspondingly provided with pairs of complementary projections developed projecting on the inner front of the opposite vertical and parallel branches thereof. The device further includes a bush, extending between the branches of band and fitted, at one end, on a collar which develops projecting along the inner front of branches, whereas the opposite end of bush constitutes the inlet for a screw the end whereof engages in a threaded hole delimited by the collar, bush being extended transversally in the tubular element, provided with aligned holes along two opposite faces, starting from a hole of the band.