Manufacturing method of core for rotary electric machine

A manufacturing method of a core for a rotary electric machine, said core includes a rotor core and a stator core, the method comprising the steps of:

• forming the rotor core by stacking a plurality of rotor plate members each having a hole portion, and
• forming the stator core by stacking a plurality of stator plate members each having a slot portion;
• forming a stator side release hole in at least a first portion of a portion of an electric steel plate in which the slot portion is formed;
• forming a rotor side hole portion in at least a part of a portion of the electric steel plate in which the hole portion is formed;
• forming a flattened portion between the stator side release hole and the rotor side hole portion, by decreasing a thickness of a portion of the electric steel plate that becomes a part of an outer periphery of the rotor core in a radial direction, after the forming the stator side release hole and the forming the rotor side hole portion;
• and
• forming the rotor plate member and the stator plate member by blanking the electric steel plate, after the forming the flattened portion.