In the Duobreton AEG splitters, the marble billets are sawn horizontally in two parts by means a series of diamond circular blades with increasing diameter. The horizontal diamond blades are mounted sequentially and in parallel position. The high-speed, precise splitting is guaranteed by the correct advancement of the billts, which are kept in contact with the conveyor belt by a series of vertical pressure units, as well as by the perfect vertical and transversal alignment of the diamond blades assured by a manual adjusting system visualized with a comparator. The machine structure is sturdy, its control is extremely simple and its maintenance very limited.