| 摘要 |
PROBLEM TO BE SOLVED: To provide a rotary cutting tool neatly taking out almost all part constituting the inside of a bottomed hole in a cutting object completely as it is in manufacturing a product by cutting the bottomed hole in the cutting object.SOLUTION: In the rotary cutting tool 10 forming an annular groove 31 in the cutting object 30 by rotating a core drill while pressing an annular groove forming blade 11a arranged at the tip of the cylindrical core drill against the surface of the cutting object 30 and making the annular groove forming blade 11a intrude to a predetermined depth, a remaining part cutting off blade 12d cutting off a remaining part 32 cylindrically remaining inside the annular groove 31 from other part of the cutting object 30 at its root portion is accommodated in the peripheral wall in the vicinity of the tip of the core drill. |
