HOLDER FOR MAGNETIC DISC BASE PLATE

摘要

PROBLEM TO BE SOLVED: To provide a machining method of a magnetic disc base plate to manufacture a magnetic recording disc medium base plate which can make high density recording at a low cost without damaging the data recording surface when grinding the edges while simplifying the next following processes. SOLUTION: For a holder having a table and a clamper to hold a magnetic disc base plate to rotate when machining the edges of the plate, this invention is characterized in that the above table and the clamper are plated 0.5μm thick or thicker and 20μm thick or thinner on the surfaces where they touch the base plate.