SUBSTRATE FOR MAGNETIC RECORDING MEDIUM, MAGNETIC RECORDING MEDIUM, AND MAGNETIC RECORDING AND REPRODUCING APPARATUS

摘要

The invention provides a magnetic recording medium substrate product which enables enhancement of contact strength between a substrate end surface and a soft magnetic layer, as well as suppression of occurrence of corrosion, a magnetic recording medium including the substrate product, which exhibits no deterioration of electromagnetic conversion characteristics and has excellent durability and a magnetic recording and reproducing apparatus including the magnetic recording medium. The magnetic recording medium substrate product includes a disk-shaped non-magnetic substrate having a circular hole in a center portion thereof, and having a chamfer formed at least one of a portion between a main surface on which a magnetic layer is to be formed and an outer end surface and a portion between the main surface and an inner end surface defining the circular hole, wherein the chamfer has a surface roughness (Ra) falling within a range of 4.0 Å = Ra<SUB/>= 100 Å, preferably 4.0 Å = Ra = 50 Å, as measured by means of an AFM.