A device is described for granulating plastic having a granulating head (1) and having a drivable cutter head (4), which cooperates with a perforated plate (2) and is arranged inside a housing (3), and which is movable along an axial guide made of guide spars (7) and guide sleeves (8), which are displaceable on the guide spars (7), and is attachable to the granulating. head (1) via locking units (9). In order to provide advantageous design conditions, it is proposed that the locking units (9) comprise latching wedges (11) mounted so they are displaceable transversely to the guide sleeves (8), which penetrate the guide sleeves (8) and the guide spar (7) in oblong holes (12, 13) in the locking position and are supported in the direction of the spar axis on one side on the guide sleeve (8) and on the other side on the guide spar (7).