| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive blank for a drill, which has high abrasion resistance and breakage resistance and high hole position accuracy, a method of manufacturing the blank, and the drill.SOLUTION: A blank 2 for a drill is made of a cemented carbide that has one end part A serving as a cutting edge part 5, the other end part B serving as a joint 9, and a central part C between the one end part A and the other end part B, serving as a flute part 6. In a method of manufacturing the blank 2, a Co content ratio at the one end part A and the other end part B is lower than a Co content ratio in the central part C. In the drill 1, the blank 2 for the drill is joined to a shank 3 and sharpened.SELECTED DRAWING: Figure 1 |
