Abstract: A refining machine for fragmented beating material comprises a rotationally symmetric, annular infeed channel for the beating material, the infeed channel being formed between a central body and an outer part surrounding the central body. The annular infeed channel has a gradually increasing inner and outer diameter in the feed direction of the beating material, and the central body and outer part are rotatably mounted relative to each other, each supporting its own annular part of a beating means which is arranged to be passed by the beating material after being fed through the infeed channel. The infeed channel redirects the movement of the beating material essentially radially outwardly in relation to the center of rotation of the beating means.