METHOD FOR MANUFACTURING GLASS SUBSTRATE FOR MAGNETIC DISC, MAGNETIC-DISC MANUFACTURING METHOD, AND APPARATUS FOR POLISHING END SURFACE OF GLASS SUBSTRATE FOR MAGNETIC DISC

摘要

　The present invention provides a method for manufacturing a glass substrate for a magnetic disc, the method enabling an improvement in shape accuracy for an end surface of the glass substrate and enabling high-quality finishing. In the present invention, a magnetism generating means comprising a pair of magnets disposed facing each other is used to form linear lines of magnetic force that advance in the thickness direction of the glass substrate, and to hold a magnetic slurry that includes a magnetic viscous fluid and polishing abrasive grains on the lines of magnetic force to form aggregations of the magnetic slurry along the lines of magnetic force. Polishing is performed at the same time on both surfaces including a side wall surface and a beveled surface of the end surface of the glass substrate by bringing the aggregations of magnetic slurry into contact with the end surface of the glass substrate while the horizontal surface of the glass substrate is inclined with respect to a surface direction orthogonal to the direction of the lines of magnetic force.