CUTTING TOOL

摘要

PROBLEM TO BE SOLVED: To improve machining accuracy by preventing chattering while suppressing a rigidity drop. SOLUTION: A head part 3 and a shank part 4 of a tool body 2 are both formed with concave grooves 15 and 16 concaved from respective external surfaces 3b and 4b separately from a chip pocket 6. The concave grooves 15 and 16 are both external surfaces 3b and 4b circumferentially opposite to a nose portion and are located in line in an interspaced relation along a center axis O with a connection 5 between the head and shank parts 3 and 4 in between. The adoption of this means reduces the weight of the head and shank parts 3 and 4 to increase the natural frequency of the tool body 2 and diverge it from the frequency of external force received from work, and to suppress resonance.