The invention relates to an arrangement (1) for a grating (2) for windows and similar openings that it is wished to secure to make entry difficult, which comprises a number of bars (4 ; 5 -5 ) extending at an angle (x) in relation to one another, and the resulting grating (2) is capable of attachment to the surrounding frame or similar of the window, etc. In accordance with the invention the bars, which are made of tubes, exhibit a number of connecting parts (7, 8) distributed along their longitudinal extent (10, 11), which exhibit curved form. The aforementioned connecting parts (7, 8) on mutually intersecting bars are flattened and are so arranged as to be connected with one another in pairs. Connection is so arranged as to take place by plaiting, and the ends of the bars exhibit a widened locking part (14). Each of the aforementioned respective locking parts (14) is so arranged as to be capable of accommodation in its own locking accommodation opening in an attachment rail extending along the edge (17) in question of the the grating (2) and capable of attachment to the window frame.