| 摘要 |
The present invention relates to a method for manufacturing a core drill and a core drill manufactured by the same. The core drill comprises a shank of which the upper surface is open and which has a cylindrical inside on which a circular groove is formed and a shaft integrally formed on the center bottom and a cutting tip protruding along the upper end of the shank upwards. A protrusion unit is formed on the upper end of the shank, and the inner circumference and the outer circumference of the protrusion unit are cut to include the different bottom level. The cutting tip encloses the inner side and the outer side of the protrusion unit to correspond to the inner circumference of the circular groove and the outer circumference of the shank and is slightly extended to the upper part. |
