Abstract: In an apparatus for the cutting, deburring or breaking of the side tooth edges of gears with one or two tools which are located on the side of a guide gear and which machine the aforesaid tooth edges. The guide gear meshes with the workpiece, and, in one embodiment, is constructed as a measuring gear. Prior to the actual machining operation, the distance between the axes of the pretoothed workpiece and the measuring gear is measured independently and is made visible, if desired, on an indicating device. In order to avoid incorrect measurement results due to burrs existing on the workpiece, the guide gear can, if desired, have recesses into which extend the burrs.