Patent ID: 8021212

Claim:
A process for producing a glass substrate for magnetic recording media, comprising: pressing the glass substrate into a resin of a solid rod-shaped grindstone with a force higher than a pressing force to be used during polishing, said resin having a hardness less than that of the glass substrate; from said pressing, forming a reentrant groove in conformity with a peripheral edge portion of the glass substrate; and polishing an outer edge surface and/or an inner edge surface of the glass substrate for magnetic recording media by pressing at a lower polishing force than said higher force said outer edge surface and/or said inner edge surface against the rod-shaped grindstone within the reentrant groove, the grindstone being made of resin, prepared by mixing abrasive grains to the resin, so that the arithmetic average roughness (Ra) of said outer edge surface and/or said inner edge surface is from 30 nm to 100 nm after polishing.