| 摘要 |
PURPOSE:To prevent a work from breaking or a cutting edge from chipping on making the most of an advantage on using a bite by providing the first cutting edge on extreme end of the bite and the second cutting edge on a line nearly parallel to the cutting face through the first cutting edge in separation. CONSTITUTION:A cutting edge 4 for cutting a bottom face is provided on the extreme end of a bite 3 and thereby is cut a bottom face (a) of a woek 1, again on a line nearly parallel to a cutting face (an inclined face b) through the cutting edge 4, is provided a cutting edge 5 for cutting the inclined face in separation to the cutting edge 4 thereby is cut the inclined face (b) of the work 1. The cutting edge 5 is made to have a rake angle alpha2 different from and bigger than the rake angle alpha1 of the cutting edge 4 so as to be suit to cut the inclined face (b), and cutting is performed in a suitable rake angle, respectively. Therefore, the cutting edge does not chip at the top due to abnormally enlarged cutting resistance not is broken at the brink of releasing from the inclined face (b). |
