| 摘要 |
PROBLEM TO BE SOLVED: To provide an abrasive core drill to be mounted on an electric tool for boring a concrete, ceramics, etc., which extends lifetime of the core drill 10 times or more as compared with conventional core drills.SOLUTION: In the present abrasive core drill, a slit is formed in a cylindrical boring part upon fixing abrasive grain formed by diamond, a cubic crystal of boron nitride, etc. to the boring part of the core drill with the use of a binding agent, etc. and the abrasive grain is fixed also to the inside of the slit. The boring can be continued by the abrasive grain in the slit even when the top end of the core drill is worn by boring, thereby remarkably extending the lifetime of the core drill as compared with a conventional abrasive core drill that cannot bore when an abrasive grain at the cylindrical top end of the core drill is worn. |
