| 摘要 |
PROBLEM TO BE SOLVED: To provide a small-diameter ball end mill capable of improving the defect resistance and the abrasion resistance of a tool itself and improving the finishing accuracy of a workpiece, and a manufacturing method thereof.SOLUTION: A tool tip part 2 made of cBN sintered body or a diamond sintered body and having a diameter rotated around an axis set to 0.1 mm or more to 6.0 mm or less includes at least a pair of cutting blades 11 including a circumferential blade 12 arranged on the circumference of the tool tip part 2 and a circular-arc bottom blade 13 arranged at the tip of the tool tip part 2, the cutting blade 11 has a surface shape in which the cutting blade 11 is rotated around the axis, a margin 15 which is a part having no continuous relief angle is connected to the cutting blade 11 over a rand, a second relief surface 16 is connected to the margin 15, and the relief angle θ of the second relief surface 16 is set to continuously change from an axis side to a circumferential side.SELECTED DRAWING: Figure 1 |
