CORE DRILL

摘要

PROBLEM TO BE SOLVED: To provide a core drill to improve initial drilling workability by facilitating positioning by reducing frictional resistance at the time of positioning a segment chip on a surface of a drilling material, to improve a cooling property by reducing frictional resistance with the drilling material on which a core body is cut and formed by facilitating discharge of cutting powder cut from the segment chip or sludge to a spiral groove formed on the core body and to improve a cutting property. SOLUTION: The core drill constituted of the cylindrical core body having a specified diameter and length and a plural number of segment chips attached with constant intervals on a lower part of the core body and to cut the cutting material constitutes its characteristic feature of making a cutting thickness surface of the segment chip of a tapered acute thickness part to decrease frictional resistance with the cutting material.