GLASS SUBSTRATE FOR MAGNETIC DISK, MAGNETIC DISK, AND METHOD FOR PRODUCING GLASS SUBSTRATE FOR MAGNETIC DISK

摘要

This glass substrate for a magnetic disk has a pair of main surfaces, a lateral wall surface, and chamfer surfaces between the main surfaces and the lateral wall surface. With respect to the surface characteristics of the lateral wall surface and/or the chamfer surfaces of this glass substrate for a magnetic disk, the arithmetic mean roughness (Ra) is 0.015μm or less and the load factor of the roughness cross-sectional area at a roughness percentage of 60% is 95% or more in the load factor curve of the roughness cross-sectional area.