This device for wire cable trays including longitudinal warp wires and transverse weft wires has a base (2) with a mounting face (16) by which it is mounted on the cable tray and fixing elements. It further includes:—at least one trough-shaped longitudinal housing intended to receive a first wire of the cable tray and produced in the mounting face,—at least one bearing surface undercut relative to the mounting face, this surface extending perpendicularly to the longitudinal housing and being disposed parallel to the back of the longitudinal housing at an intermediate level between the back of that housing (18) and the mounting face, and—at least one transverse cut-out corresponding to each intersection between a longitudinal housing and a bearing surface, this cut-out extending from one edge of the mounting face to a longitudinal housing.