Production manner of glass substrate for magnetic recording medium and glass substrate for magnetic recording medium, and production mannered null reluctance die

摘要

PROBLEM TO BE SOLVED: To provide a glass substrate for a magnetic recording medium capable of suppressing troubles caused by foreign materials on a substrate surface in the magnetic recording medium corresponding to a magnetoresistive head (MR head) or a giant magnetoresistive head (GMR head) as much as possible.;SOLUTION: The glass substrate for the magnetic recording medium is used for the magnetic recording medium corresponding to the magnetoresistive head (MR head) or the giant magnetoresistive head (GMR head). Surface roughness Ra of a chamfered part and/or a side wall part of an inner peripheral end surface and/or an outer peripheral end surface of the glass substrate is 0.001-0.04 μm.;COPYRIGHT: (C)2007,JPO&INPIT