Hermetically sealed head disk assembly

A sealed head disk assembly having a base casting that provides attachment points for major components of the head disk assembly and a cover for enclosing major components of the head disk assembly. The base casting has a hermetic seal encompassed by an outer perimeter of the base casting. The hermetic seal is juxtaposed to at least one complementary surface on the cover. The cover has a semi-hermetic seal inside a perimeter of the complementary surface for the hermetic seal. The semi-hermetic seal is juxtaposed to at least one complementary surface on the base casting. The sealed head disk assembly includes a screw causing deflection in a zone of the cover and provides spring force allowing registering the hermetic seal against a complementary surface of the hermetic seal on the base casting and the semi-hermetic seal against the complementary surface of the semi-hermetic seal on the base casting.