GLASS SUBSTRATE FOR MAGNETIC RECORDING MEDIUM, MAGNETIC RECORDING MEDIUM, METHOD FOR MANUFACTURING GLASS SUBSTRATE FOR MAGNETIC RECORDING MEDIUM, AND DEVICE FOR MANUFACTURING GLASS SUBSTRATE FOR MAGNETIC RECORDING MEDIUM

摘要

The purpose of the present invention is to provide a glass substrate for a magnetic recording medium wherein minor scratches are minimized between a main surface and an outer peripheral chamfered portion. Provided is a glass substrate for a magnetic recording medium formed in a donut shape and having a pair of main surfaces, an outer peripheral end surface, and an inner peripheral end surface, wherein the outer peripheral end surface includes an outer peripheral lateral portion and a pair of outer peripheral chamfered portions, and when chamfer widths in at least one of the pair of outer peripheral chamfered portions are measured at a plurality of m easuring points, the difference between the maximum measured value and the minimum measured value is 10 μm or less.