The present invention pertains to a bonemill (1) intended particularly to grind slaughter residue in the form of bones and bone-like residue products. Such a device features among others a processing channel (2), equipped with a transport element (3) for transportation of a millable material (4) toward a milling unit (6). The milling unit comprises two parallel spindles (9) which in turn feature milling bodies (7) arranged in pairs with substantially evenly distributed replaceable milling inserts (8). The milling inserts protrude from the cylindrical surface of the milling body while being separate from each other by tracks (14) and intermediate ridges (15) formed in the surface of the milling body. The processing channel (2) is arranged to form a screw housing surrounding the millable material (4), and featuring a milling inlet (16) oriented toward the milling unit. The inlet has an extension in the rotational plane of the milling bodies which is shorter than the total extension of the milling bodies in thei
