A method of manufacturing of a hard-disk drive using a bulk eraser for erasing recorded information on a magnetic-recording disk. The method includes providing a bulk eraser that produces magnetic-flux density in a gap sufficient to erase recorded information from a magnetic-recording disk, a hard-disk drive, a disk-stack having at least one magnetic-recording disk, and a drive motor for rotating the magnetic-recording disk. The method also includes configuring a plurality of magnets and a structure of the bulk eraser such that magnetic-flux density is oriented parallel to and in a radial direction of the magnetic-recording disk; and rotating the magnetic-recording disk. The method further includes inserting the hard-disk drive into the gap of the bulk eraser; and erasing recorded information from the magnetic-recording disk located in the gap; and removing the hard-disk drive from the gap.