Abstract: The invention relates to a diamond wire of the type used in single- or multiple-wire machines for cutting blocks of hard materials, such as stone, concrete, metal or similar, in order to obtain sheets with a thickness of between 2 and 3 cm. The structure of the wire comprises a steel cable and a number of beads distributed along the length of the cable, as well as a plastic coating which is applied to the cable and secures the heads in relative positions both in terms of the longitudinal movement and rotation thereof in relation to the cable. The invention is characterised in that: each bead comprises a generally cylindrical single body of diamond material including an axial passage provided with various formations in the form of angularly equispaced ribs that project inwards and extend longitudinally; and that the external surface of the cylindrical body includes multiple corresponding angularly equispaced channels that also extend longitudinally.