TRIMMING METHOD AND DEVICE THEREFOR

PURPOSE: To surely cut and remove burr on the external circumferential face of a work and to prevent the front face of the work from causing a flaw at the time of ironing in the following process. CONSTITUTION: In a trimming method where a shaft like work W is set on a trimming die 26 and the burr R formed on the circumference of the work W is cut and removed while moving the work in the axial direction by pressing the work with a punch 16, each die piece 26p of the trimming die 26 divided into plural numbers in the circumferential direction is moved to the outside of the radial direction only by the equal dimension. Then, in a state where a prescribed clearance is generated between the work W and the trimming die 26, a process to set the work W on the trimming die 26, and after this process, a process to make the clearance between the trimming die 26 and the work W into almost zero by moving each die piece 26p of the trimming die 26 to the inside of radial direction and continuing each die piece 26p mutually are provided.