Provided are an opposed iron core transmitting rotation motion, a manufacturing method thereof, and an electromagnetic fan clutch formed by the opposed iron core. The opposed iron core includes iron core grooves (12; 13) axially arranged in a back-to-back manner on an electromagnetic iron core body (11). The manufacturing method of the opposed iron core includes: directly drawing the iron core body (11) to form the iron core grooves arranged in the back-to-back manner, or directly spinning the iron core body (11) to form the iron core grooves arranged in the back-to-back manner. The electromagnetic fan clutch formed by the opposed iron core has a first actuation gap (841) and a second actuation gap (842) respectively on two sides of the electromagnetic iron core body (11) of an opposed iron core apparatus.

A magnetic core excellent in productivity, having stable magnetic characteristics, and easy to handle for a coil device including a conductor and is formed by stacking a plurality of soft magnetic thin ribbons divided into small pieces.

An inductor includes a first magnetic body having a toroidal shape and having a ferrite; and a second magnetic body configured to be different from the first magnetic body and including a metal ribbon, wherein the second magnetic body includes an outer magnetic body disposed on an outer circumferential surface of the first magnetic body and an inner magnetic body disposed on an inner circumferential surface of the first magnetic body, and each of the outer magnetic body and inner magnetic body is wound in a plurality of layers in a circumferential direction of the first magnetic body.