Glide testing of disks with calibration confirmation testing by inducing collision of the slider with production disk surface

A method of manufacturing a disk for a disk drive comprising the steps of:

• measuring a maximum mean asperity height on a set of disks produced by a fabrication process;
• selecting a range of maximum mean asperity heights covering a majority of the set of disks;
• selecting a production calibration disk with a maximum mean asperity height within the range of maximum mean asperity heights covering a majority of the set of disks;
• executing a calibration process for a glide test system using one or more calibration disks to determine a glide test rotation rate for glide testing at which a glide head flies at a predetermined height, and a clearance confirmation rotation rate range for confirmation testing at which the glide head collides with asperities on the selected production calibration disk;
• and
• glide testing disks produced by the fabrication process using the glide test rotation rate for glide testing and on selected disks performing a confirmation test to detect changes in performance of the glide test system including the steps of:
• moving the glide head to a predetermined track;
• determining a clearance rotation rate for the selected disk by reducing the rotation rate of the disk until collisions with asperities on the disk are detected;
• and
• repeating the calibration process when the clearance rotation rate for the selected disk is outside of the clearance confirmation rotation rate range.