An actuator block including at least one slot between each adjacent pair of actuator arms and located behind a site for a flexure stiffener. The resulting hard disk drive shows an improved NRRO. The invention further includes the actuator block including two of the slots between each adjacent pair of actuator arms. The invention includes an actuator assembly formed from the actuator block coupling to at least one head gimbal assembly on each actuator arm. The actuator assembly further includes a main flexure coupling through the flexure stiffener to the actuator block. The invention further includes the hard disk drive including the actuator assembly. The invention includes making the actuator assembly from the actuator block and the hard disk drive from the actuator assembly. The actuator assembly and the hard disk drive are products of these processes.