A harness frame for weaving machines includes a pair of horizontal vertically spaced upper and lower beams, and a pair of vertical cross beams (1) between which these horizontal beams (2) are mounted. A detachable connection is provided between each of the extremities of the beams (2) and the side of the cross beams (1) adjoining these extremities, including at least one screw (3,4) which extends in the extremity of the beams (2) through a connecting-piece (5) which is mounted in such a manner on this cross beam (1) that, on the one hand, substantially no stresses are transferred between the connecting-piece and the cross beams when tightening the screw (3,4) and when moving the harness frame and that, on the other hand, the beam (2) and the cross beam (1) are pulled towards each other by means of the connecting-piece (5). A solid connection is thus formed between the beam (2) and the cross beam (1) upon tightening of the screw (3).