A hard disk drive has a motor mounting bracket with mounting screws that
attach from outside the drive and external to the seal with a screw bolt
pattern diameter that is larger than an outer diameter of the motor hub.
This configuration greatly reduces contamination inside the disk drive
since all contaminants due to the screws are sealed from entering the
disk drive. Consequently, the bottom of the mounting bracket is extended
to the form factor limit to increase the internal space that is provided
for the stator/winding of the motor. In relatively high platter count
disk drives, the bottom disk is positioned very close to the motor
bracket with this approach, which normally would cause the air drag to
increase drastically and thereby impede the performance of the disk
drive. Bosses may be used on the bracket to accommodate blind tap hole
depths from the external surface of the bracket.