composing piece rotary stacking skewing and press fitting are carried out by a punch 14 and a rotary die 15 in this case in order to make an integral coupling of thin iron core plates a punched into the rotary die 15 with a press fitting the cut and rise projections 13 of a subsequent thin iron core plate a are fitted to the cut and rise projection holes 12 of a preceding iron core plate a the coupled thin iron core plates a are stacked on a receptacle table 17 ascending or descending within a cylindrical squeezing ring 16 the desired number of thin iron core thin plates a are stacked resulting in forming a laminated core l as a result the receptacle table 17 is lowered hydraulically and the laminated core l is taken out of the device fig3 shows a laminated core l formed by a method wherein the thin iron plates a are rotated by a predetermined rotary stacking angle and a corresponding skew angle theta and stacked a configuration of the mechanism for performing rotary stacking and skewing of the thin iron plates a in the rotary die 15 will be described as follows as shown in the sectional view for indicating the rotary die part of fig4 the squeezing ring 16 having the die 15 fitted at the upper part thereof is rotatable by bearings 16a with respect to the die holder 4 of the lower die 2 and a pulley 18 is fitted to an outer periphery of the squeezing ring 16 to a side wall of the table 1 is fastened a rotation applying device 19 with fixing screws 20 as shown in fig5 a timing belt 24 is wound between.