Abstract: An improved actuator apparatus is employed in a hard disk drive device for positioning read/write heads over tracks on a data storage disk of the disk drive. The actuator apparatus includes an all plastic C-block assembly providing the actuator apparatus with a reduced weight, lower inertia and better damping characteristic which enable improved dynamic performance. The C-block assembly includes a body portion and a pair of tapered support arms extending from the body portion in a parallel orientation. The support arms each have a suspension for a read/write head staked thereto within a mounting surface aperture at a distal end of the arm. The mounting surface aperture is configured to have a non-circular shape to facilitate staking of the read/write head to the support arm and enable construction of the C-block assembly out of plastic.