Segment type grindstone

PROBLEM TO BE SOLVED: To provide a segment type grinding wheel capable of improving a grinding ratio by increasing the concentration of super abrasive grains even though the amount of the expensive super abrasive grains usage is decreased to reduce a grinding wheel price, and grinding at high speed without causing grinding seizure. SOLUTION: In the grinding wheel affixing a plurality of grinding wheel tips 11 having a grinding wheel layer uniting super abrasive grains 14 by a bonding agent 15 on a base element, a plurality of holes 17 penetrating the grinding wheel layer are dispersively provided on a grinding surface, an area ratio of the total opening area of the plurality of holes to the total grinding area of the plurality of grinding wheel tips is made to be 0.05 to 0.6. COPYRIGHT: (C)2004,JPO