Abstract: A data recording disk file includes a disk stack subassembly and a linear actuator, both of which are supported by a single-piece casting which forms part of the disk file housing. The casting is symmetric about two perpendicular planes and includes an open-ended portion and an actuator portion. The disk stack subassembly, which includes an in-hub motor, is entirely supported in the open-ended portion by two parallel interior walls which are equally spaced from the first plane of the casting. The linear actuator is entirely supported in the actuator portion by two parallel side walls which are equally spaced from the second plane of the casting. The actuator is mounted to the side walls in its plane of symmetry, which coincides with the first plane of the casting, and with its linear access axis coincident with the intersection of the two planes.