| 摘要 |
PROBLEM TO BE SOLVED: To provide a scribing cutter, which is capable of forming deep vertical cracks into a work and obtains a plurality of edges defining a recess formed into the work. SOLUTION: The scribing cutter 12 has a square bottom face 12a and side faces 12b, and so on. The corners of the bottom face 12a adjoining the side faces 12b... are chamfered to form edges 41 and so on of a square cone near the corners of the bottom face 12a. The edges 41 and so on of the cone are contacted to a work 11 and bitten into the work to form a recess deeper in the vertical direction, but less in the horizontal direction than a recess formed by biting the edges of the conventional triangular cone. This makes possible a vertical deep crack into the work 11 and prevents horizontal cracks from occurring in the work. |
