Patent ID: 6807028
Filing Date: 2004-10-19
Classification: G11B

Abstract:
A center core for a magnetic disc which is held by the magnetic attraction force of a magnet provided at the tip of a spindle to which said spindle transmits a rotational driving force comprising:a standardizing surface portion formed as a disc in the central portion thereof, that abuts the tip surface of said spindle to perform standardizing positioning; an attraction surface portion formed annularly around the outer periphery of said standardizing surface portion via a step portion so that it is parallel to said standardizing surface portion while of a different height, that faces said magnet provided at said spindle; and a collar portion formed as a flange around an outer periphery thereof, parallel to said standardizing surface portion, that is fixed to the central portion of a discoid magnetic recording media; wherein said step portion between said standardizing surface portion and said attraction surface portion is of a multiple step drawn form.