| 摘要 |
PROBLEM TO BE SOLVED: To provide a long-lived coated drill in making the best use of its function inherent in a hard coat, by controlling the thickness of each coating of a cutting face and a margin part at the time of coating to increase the thickness. SOLUTION: In a drill coated with a hard coating layer, it is featured that thickness of a coating layer in a drill tip part and/or the vicinity is thinned in a honing part installed in a flank and a boundary between the flank and a cutting face, but thickened in the cutting face and a margin part, and likewise, in another coated drill coated with the hard coated layer on a drill installed with a second cutting edge in the contact neighboring part of a peripheral edge and a tip edge in the radial direction and/or the axial direction, it is so constituted that thickness of the coating layer is thinned in the honing part and the margin part installed in the flank and the boundary between the flank and the cutting face and another cutting face of a second cutting edge, but thickened in the cutting face of the tip part and the margin part, respectively.
|
