A sealed head disk assembly has a cover for enclosing major components of the head disk assembly. The cover has a hermetic seal encompassing an outer perimeter of the cover and a semi-hermetic seal inside a perimeter of the hermetic seal. The hermetic seal and semi-hermetic seal are juxtaposed to at least one complementary surface on the base casting. The base casting, which provides attachment points for the major components of the head disk assembly has at least one complementary surface.