Abstract: A head disk assembly (HDA) for a hard disk drive includes vibration damping structure. The HDA also includes an enclosure, a disk, a pivot bearing cartridge, and a head stack assembly (HSA). The enclosure includes a base that preferably includes integral side walls. The disk has a recording surface that has an annular landing zone. The pivot bearing cartridge includes a shaft fixed to the enclosure, and the head stack assembly is connected to the pivot bearing cartridge for rotation relative to the shaft. The HSA includes a head supported to be moved radially relative to the recording surface and to be brought to rest at a position in the landing zone. The base has a plurality of interior-facing surfaces including a major interior-facing surface parallel to the recording surface. Significantly, one of the interior-facing surfaces of the base serves as a bearing surface against which the vibration damping structure is compressed.