An actuator apparatus used with a hard disk drive. The actuator apparatus includes a pivotable actuator arm, a magnetic head mounted onto a first end of the actuator arm, an overmold connected to a second end of the actuator arm and including a metal piece, a voice coil motor (VCM) having a coil coupled to the overmold and at least one magnet positioned to face the coil, and a stopper positioned to be spaced apart at a predetermined interval from the overmold of the actuator arm when the magnetic head is positioned at a parked position, to limit pivoting of the actuator arm. Specifically, the stopper may be positioned to be spaced at the interval from the overmold of the actuator arm positioned at a position where a torque acting on the actuator arm due to the metal piece and the magnet is substantially 0. Accordingly, the torque acting on the actuator arm within the interval is in an opposite direction to a direction in which the actuator arm pivots to a parked position, thereby reducing the pivoting speed of the actuator arm. Thus, noise and impulse caused by the contact of the actuator arm and the stopper reduce.