This International Standard specifies the mechanical, physical and magnetic characteristics of a lubricated magnetic disk of 130 mm (5.12 in) outer diameter and 40 mm (1.57 in) inner diameter intended for mounting in data storage devices. This International Standard defines the requirements for a disk to give satisfactory performance at 83 332 flux transitions per track. When used at other densities, equivalent performance may require changes to the mechanical, magnetic and electrical criteria. NOTE — The original design of the subject of this International Standard was made using the Imperial measurement system. Some later developments, however, have been made using SI units. In the process of conversion into the alternative system, values may have been rounded. Therefore, the two sets of figures are consistent with, but not exactly equal to, each other. Either set may be used, but the two should neither be mixed nor reconverted.