Mounting spindle shaft in magnetic disk drive

A magnetic disk drive comprising:

• a spindle motor having a spindle shaft, on which a magnetic disk is mounted, and which has one end subjected to facial roughening;
• a carriage supporting a magnetic head for reading and writing data from and on the magnetic disk;
• a base housing therein the spindle motor and the carriage;
• a cover mounted on the base;
• and
• a screw for fixing the spindle shaft to the cover in a state where the cover is in contact with the portion of the spindle shaft subjected to the facial roughening.

A magnetic disk drive comprising:

• a spindle motor having a spindle shaft, on which a magnetic disk is mounted, and which has a groove at one end thereof;
• a carriage for supporting a magnetic head for reading and writing data from and on the magnetic disk;
• a base for housing therein the spindle motor and the carriage;
• a cover mounted on the base, having a plurality of projections on a portion opposite to the groove in the spindle shaft;
• and
• a screw for fixing the spindle shaft to the cover in a state where the projections of the cover are fitted at least partially in the groove of the spindle shaft.