The improved disk drive system has an improved actuator arm assembly where the arms are independently and individually insertable and removable from the actuator member. Furthermore, each arm is individually self-locked into the actuator member without the need for external retaining means such as screws, springs, and rings. Since the arms are individually insertable/removable, the arms can be made very thin thereby allowing easy attachment of the head suspension assembly to the arm without the need for swaging, bonding, welding or screw-in. Since the arms can be made very thin, that provides substantial reduction in disk to disk spacing and therefore, substantial reduction in the overall height of a disk drive system.