The invention includes a method making a balanced disk pack for a hard
disk drive, from a disk pack including a spindle motor rigidly coupled,
and aligned by at least two open screw holes, with a disk clamp. The
invention includes the resulting balanced disk packs, as well as hard
disk drives built with such balanced disk packs. The invention also
includes apparatus providing the means for implementing the steps of
making a balanced disk pack from a disk pack. The invention includes at
least one mechanical counterbalance for use in balancing the disk pack of
a hard disk drive.