Patent ID: 8248726
Filing Date: 2012-08-21
Classification: G11B

Abstract:
1. A hard disk drive, comprising: an information recording medium that is rotationally driven for recording and/or reproducing information; and a rotor hub having a flat mounting surface disposed in an outer circumferential portion thereof and on which the information recording medium is mounted so as to contact an edge portion of the mounting surface, the mounting surface being made of an austenitic stainless steel containing a machineability improving additive, except for selenium and tellurium, for improving the machineability of the mounting surface, at least one of the edge portion or a portion of the mounting surface in the vicinity of the edge portion containing surface pores formed by component particles of the additive falling from the mounting surface, each of the pores having a length less than 10 μm in a circumferential direction of the mounting surface.