NOVELTY - The machine comprises a rotary pressing body turning around a rotational axis (1') and comprising a grinding roller and a compressor (1) of cylindrical form, and a horizontal plane matrix (3) comprising many openings for extrusion or granulation. The rotational surface is constituted of many recessed surface portions (2) and complementary surface portions (4). The grinding roller and compressor are used for gripping, crushing and pressing the compact material through the openings as a result of its rolling on the matrix or on a plane parallel to the immediate vicinity of the matrix.    USE - The machine is useful for granulating a wood compact material, which is useful to produce wood pellets used as fuel for heat distribution.    ADVANTAGE - The machine ensures effective and economical granulation of a wood compact material thus capable of easily producing the wood pellets at high yield.    DETAILED DESCRIPTION - The machine comprises a rotary pressing body turning around a rotational axis (1') and comprising a grinding roller and a compressor (1) of cylindrical form, and a horizontal plane matrix (3) comprising many openings for extrusion or granulation. The rotational surface is constituted of many recessed surface portions (2) and complementary surface portions (4). The grinding roller and compressor are used for gripping, crushing and pressing the compact material through the openings as a result of its rolling on the matrix or on a plane parallel to the immediate vicinity of the matrix. The rotating recessed surface portions and the complementary rotating surface portions are configured to provide an action for striking the clamped or compressed material between the roller and matrix, and form many teeth profiled in the direction of the rotation axis and located between two notches. The portions of complementary surface are flat, and the external surface of each tooth forms a complementary surface portion. The cross-section of a notch is present in V shape, and comprises a front branch and a rear branch in the direction of axial rotation of the grinding roller and compressor. The branches form the longitudinal front and rear sides respectively of the corresponding notch. The rear branch extends radially so that the back side of the corresponding notch is located in a radial plane passing through the face and rotation axis of a grinding roller and compressor. The angles of opening, the circumferential distribution and the dimensions of the notches are determined in such a way that an opening angle of V is 50 degrees , a depth of notches is 7 mm and an angular deviation between two notches is 16.5 degrees . The external diameter of each roller is 100-130 mm. Each grinding roller and compressor is removable on its radial support shaft forming the rotational axis. The rotating pressing body comprises two compression rollers. The granulation openings of the plane matrix comprise a truncated part at each end connected by a central cylindrical part. The outer diameter of conical parts is 8 mm. The diameter of the central cylindrical part is 6 mm.    DESCRIPTION OF DRAWING(S) - The figure shows a partial sectional view of a machine for granulating a wood compact material.    Compressor (1)    Rotational axis (1')    Recessed surface portions (2)    Plane matrix (3)    Complementary rotating surface portions. (4)