The invention relates to a gearwheel and to a method and device for producing gearwheels (6) that have undercut tooth flanks (7, 8). The workpiece is rotationally driven by a workpiece spindle, and a tool comprising a rotating fly cutter (4) is rotationally driven by a workpiece spindle (3) in a substantially fixed speed ratio to the workpiece spindle. The tool is displaced relative to the workpiece in the direction of the rotational axis (2) of the latter in such a manner that the fly cutter (4), with its cutting edge (10), lifts off one chip each along a first tooth flank (7) of a tooth (9) to be produced with every rotation. The second tooth flank (8) to be produced of said tooth extends at least in some sections at an acute angle to at least one section of the first tooth flank (7). The aim of the invention is to improve the aforementioned method and device in terms of its cost effectiveness and to provide a synchromesh gearwheel having improved stability. For this purpose, the second tooth flank (8) of every tooth (9) is produced independently of the first tooth flank (7). During production of the two tooth flanks (7, 8), the phase position of the rotational movement of the workpiece spindle (3) to the rotational movement of the workpiece spindle is varied during advance (c).