Abstract: A disk drive includes a base, a spindle motor coupled to the base, a disk mounted on the spindle motor, a pivot assembly coupled to the base, and a head stack assembly. The head stack assembly includes an actuator body defining a bore for surrounding the pivot assembly, a supporting surface, and an actuator arm cantilevered from the actuator body and defining a longitudinal axis. The bore defines a pivot axis of the head stack assembly. The pivot assembly includes a stationary member coupled to the base, the stationary member having a length, and a rotatable member positioned on the supporting surface such that the rotatable member is between the stationary member and the supporting surface. The stationary member and the rotatable member define a projecting member and a recessed portion, the projecting member and the recessed portion interacting to allow the head stack assembly to pivot about the pivot axis.