This parer describes the cutting characteristics and economics of resharpened ball end mill. Original ball end mill made of cemented carbide and coated with (Ti, Al) N, and resharpened ball end mill are used in experiments. The workpiece is hot working tool steel. Its hardness is HRC43. Several machining characteristics, such as tool wear, chipping, and cutting forces were examined. The machining costs to the metal removal amount were compared. It became clear that 1) tool wear, chipping and cutting foeces of the original ball end mill are less than that of the resharpened one, 2) the use of the resharpened ball end mill is more economical.
