| 摘要 |
PROBLEM TO BE SOLVED: To efficiently and surely form dimples on a processing object surface of a narrow part of a side face or the like of a groove part.SOLUTION: A burnishing tool includes a mandrel 2, and a frame externally fitted and fixed to the mandrel 2 for holding a plurality of balls 3 in contact with an outer peripheral surface 23 of the mandrel 2, and forms dimples 71 by bringing the balls 3 on the outer peripheral surface 23 into contact with a projecting object surface 7 with rotation of the mandrel 2 and the frame. In this case, the diameter of the outer peripheral surface 23 of the mandrel 2 is set so that difference between the front side and the rear side with respect to a distance L in a direction vertical to the processing object surface 7 between a contact surface 23a of the outer peripheral surface 23 with the balls 3 on the processing object surface 7 side, and the processing object surface 7 in a state where the mandrel 2 bends in forming the dimples 71 is set smaller than that in a state before the mandrel 2 bends. |
