The invention relates to a ring ratchet spanner comprising a ratchet head (1) that is closed all the way round, a lever arm (2) that is seated on the ratchet head (1) and is intended for actuating the spanner, a spanner part (3) that is rotatably mounted in the ratchet head (1), a serrated ring (4) that is provided on the outer circumference of the spanner part (3), and a locking element (5) that interacts with the serrated ring (4). The object of the invention is to create a ring ratchet spanner that can be comfortably placed on any nut and easily actuated when working on a wide variety of pipelines. This object is solved by the closed ratchet head (1) consisting of two halves (6, 7) that can be separated from each other, by one of the two halves (6, 7) of the ratchet head (1) being connected to the lever arm (2), by the spanner part (3) that is rotatably mounted on the ratchet head (1) likewise consisting of two halves that can be separated from each other, and by the two halves (6, 7) of the ratchet head (1) being able to be joined together again in a fixed manner after they have been separated and subsequently placed against the nut to be loosened or tightened.