| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic fluid for glass substrate polishing, which enables smooth processing of an end surface of a glass substrate and which can make processing time shorter than ever.SOLUTION: A polishing wheel 12b includes: a rotating shaft 1; a magnetic field forming portion 2 that comprises first and second disc-like members 2a and 2b rotating with the rotating shaft 1; and a magnetic fluid 3. A concentration of magnetic abrasive grain in the magnetic fluid 3 is 70 wt% or more, and a shape can be retained to some extent even in a state with no restraint caused by a magnetic field. |
