| 摘要 |
PROBLEM TO BE SOLVED: To improve workpiece material machining to generate long chips by attaining a constant functional edge angle along the waveform edge line, and combining with chip forming further optimized by high cutting speed. SOLUTION: A tip contains a chip upper surface 16, a bottom face and a side face between the two. The cutting tip is provided with axially projecting portions 22, 23 on respective ends and respective projecting portions 22, 23 include slants 26, 27. Main cutting edges 24, 25 are provided on the crossing part between the chip surface 16 and the side face. A flank 30 having a protrusion formed on respective sides is provided extendingly to a second spiral twisted flank through a step recess and chip angle increases accompanying with the cutting depth. The upper side surface 16 contains surfaces 34, 35 flatly slant along the main cutting edges 24, 25 with a constant width and the flatly slant surfaces cross surfaces 36, 37 for rupturing an inwardly slanted second chip. |
