| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a glass blank for a magnetic disc having high surface flatness, uniform thickness, and excellent surface roughness. <P>SOLUTION: A glass blank for a magnetic disc comprises a pair of a main surface and an end surface, and becomes a glass substrate for a magnetic disc, where flatness of the main surface is 4 μm or less and deviation of thickness is 6 μm or less. <P>COPYRIGHT: (C)2013,JPO&INPIT |
