To make the device applicable to various types of operation needles by providing the device with a first die having first and second members and a second die having at least one surface and swaging the operation needle arranged between both dies by the relative motion of both dies.

The die 12a of a pair of the swaging dies 12a, 12b is constituted by movably providing a base die member 14a with a thin and slender box-shaped sliding die member 16a. A swaging portion 18a having an engaging surface 20a and a contact surface 22a is formed at one end of this sliding die member 16a, this swaging portion 18a is formed to a thickness indicating the land width of the operation needle to be swaged. A projecting part 30a having a chip portion 32a and a pair of flanks 34a, 36a is formed at a main body 26a of the base die member 14a and the flank 34a is inclined to approximately 45° with the axis in the longitudinal direction of the main body 26a. On the other hand, the flank 36a of the projection 30a is inclined at a sharp angle with the axis in the longitudinal direction of the main body 26.