MAGNETIC DISK SUBSTRATE AND PRODUCTION METHOD OF MAGNETIC DISK

摘要

The invention provides a magnetic disk glass substrate capable of preventing the occurrence of dust and adhesion of particles to the magnetic disk surface during a magnetic disk production process, a production method and a magnetic disk. A glass substrate for a magnetic disk has a construction in which an outer peripheral edge shape formed around a peripheral edge portion of a main surface has, with another flat portion of the main surface being the reference: an outer peripheral edge portion ski jump value of not greater than 0 (m; an outer peripheral edge portion roll-off value of (0.2 to 0.0 (m; and an outer peripheral edge portion dub-off value of 0 to 120 A; and the glass substrate has a chamfer surface between the main surface (data surface) and the outer peripheral edge surface (straight surface), and has an R surface having a radius of curvature of 0.013 to 0.080 mm between the data surface and the chamfer surface of the glass substrate.