A disk spindle assembly for a hard disk drive includes a hub and a hub flange extending radially from the hub and configured to apply a clamping force to secure disk media to the hub. The hub flange includes multiple protrusions extending from a surface of a top side and configured to contact a disk medium at multiple contact positions in response to application of a clamping load. The protrusions may be annular protrusions circumscribing the hub, where the height of an inner protrusion may be less than the height of an outer protrusion to inhibit coning of the bottom disk medium, and the protrusions may be positioned so that an equivalent contact radius corresponding to contact radii of the inner and outer annular protrusions is at a position halfway between the inner and outer diameters of the disk spacers to inhibit coning of the middle disk media.

A disk spindle assembly for a hard disk drive includes a hub and a hub flange extending radially from the hub and configured to apply a clamping force to secure disk media to the hub. The hub flange includes multiple protrusions extending from a surface of a top side and configured to contact a disk medium at multiple contact positions in response to application of a clamping load. The protrusions may be annular protrusions circumscribing the hub, where the height of an inner protrusion may be less than the height of an outer protrusion to inhibit coning of the bottom disk medium, and the protrusions may be positioned so that an equivalent contact radius corresponding to contact radii of the inner and outer annular protrusions is at a position halfway between the inner and outer diameters of the disk spacers to inhibit coning of the middle disk media.

A disk clamp for a hard disk drive, configured to clamp disk media to a spindle, includes multiple protrusions extending from a surface of a bottom side and configured to contact a disk medium at multiple contact positions in response to application of a clamping load. The protrusions may be annular protrusions circumscribing a disk clamp hub, where the height of an inner protrusion may be less than the height of an outer protrusion to inhibit coning of the top disk medium, and the protrusions may be positioned so that an equivalent contact radius corresponding to contact radii of the inner and outer annular protrusions is at a position halfway between the inner and outer diameters of the disk spacers to inhibit coning of the middle disk media.

Provided is an annular spacer to be disposed such that a main surface of the spacer is in contact with a magnetic disk in a hard disk drive device, the spacer including two main surfaces; an inner circumferential surface; and an outer circumferential surface, in which a chamfered surface is present between the outer circumferential surface and each of the two main surfaces, and at least a portion of an outer circumferential region of at least one of the two main surfaces includes an inclined region that is inclined toward the other main surface side in a radial direction from a center of the spacer to the outer circumferential surface side.

Provided is an annular spacer to be disposed such that a main surface of the spacer is in contact with a magnetic disk in a hard disk drive device, the spacer including two main surfaces; an inner circumferential surface; and an outer circumferential surface, in which a chamfered surface is present between the outer circumferential surface and each of the two main surfaces, and at least a portion of an outer circumferential region of at least one of the two main surfaces includes an inclined region that is inclined toward the other main surface side in a radial direction from a center of the spacer to the outer circumferential surface side.

Provided is a glass for a magnetic recording medium substrate, which is an amorphous glass, in which an SiO.sub.2 content is in a range of 54 mol % or more and 62 mol % or less, an MgO content is in a range of 15 mol % or more and 28 mol % or less, an Li.sub.2O content is in a range of 0.2 mol % or more, and an Na.sub.2O content is in a range of 5 mol % or less.

A ring shaped glass spacer is configured to be arranged in contact with a magnetic disk in a hard disk drive apparatus. A surface resistivity of a surface of a glass material of the glass spacer at 22 (° C.) is lower than a surface resistivity of an inner portion of the glass material at 22 (° C.).

A ring shaped glass spacer is configured to be arranged in contact with a magnetic disk in a hard disk drive apparatus. A surface resistivity of a surface of a glass material of the glass spacer at 22 (° C.) is lower than a surface resistivity of an inner portion of the glass material at 22 (° C.).

An apparatus includes a plurality of storage media mounted on a rotatable spindle. The apparatus also includes an actuator with at least one actuator arm configured to translate among the plurality of storage media and at least two heads supported on the at least one actuator arm. Each of the at least two heads is configured to communicate with the plurality of storage media.

An apparatus includes a plurality of storage media mounted on a rotatable spindle. The apparatus also includes an actuator with at least one actuator arm configured to translate among the plurality of storage media and at least two heads supported on the at least one actuator arm. Each of the at least two heads is configured to communicate with the plurality of storage media.