PURPOSE: To manufacture a high accurate sprocket for roller chain in low cost by punching plural teeth to outer peripheral edge of flat plate stock and executing coining after forming tapered faces having excess thickness parts corresponding to deforming quantity at tooth tip parts.

CONSTITUTION: The flat plate stock is held with a die 16 and a plate holding plate 24 in the punching device and punched with an ejector 18 and a punch 22. By this method, the sprocket 6 having plural teeth on the outer peripheral edge, is formed. Then, the tapered faces 11 are formed at one side either the front or the rear of the tooth tip parts 10 and also the excess thickness parts 12 corresponding to deforming quantity at tooth tip parts 10, which executes the coining at the next process to the tip parts. The above sprocket 6 is set to a die 29 and an ejector 33 in the coining device and a punch 30 is descended to execute coining. To the above tooth tips 10, the coining is executed at between curved surface 29b in the die 29 and curved surface 30b in the punch 30, and then, plastic deformation is executed to the above excess thickness parts 12 so as embed the spaces S at between recessed faces 29b and the tapered faces 11. By this method, the sprocket 6 for roller chain is worked at high accuracy in two processes.