| 摘要 |
PURPOSE:To improve the surface roughness of section as well as the uniformity of saw mark and prevent an abrasive grain layer from breakage by a method wherein the edges of the inner periphery of a base metal are rounded with the same radius of roundness in order to remove the protuberances thereon. CONSTITUTION:The inner peripheral edge diamond grindstone is formed with the abrasive grain layer 3 by adhering diamond abrasive grains to the inner periphery of a hole 2 in the ring-shaped base metal 1 and the vicinity of the hole 2 while the edges of the hole 2 are rounded along the circumferential direction thereof as shown by numerals 5. Rounding of respective edges is effected with the same radius of curvature in order to prevent the ununiformity of the abrasive grain layer 3 in the left and right sides thereof. Stress concentration in a part of the abrasive grain layer 3 is eliminated by providing both edges of the hole with the same roundness 5 having the radius R and, therefore, the breakage of the abrasive grain layer 3 may be prevented more surely. |
