ROTARY CUTTING TOOL

PROBLEM TO BE SOLVED: To provide a rotary cutting tool which can suppress the generation of chatter, and further can prevent the enlargement of the diameter of a hole in machining the hole, and is very excellent in the practicability. SOLUTION: In the rotary cutting tool, a large number of helicoidal chip removing grooves 2 having a required width from a start end to a final end are provided on the outer periphery of a nearly cylindrical tool body 1, and gash surfaces 18 are formed on the tip end sides of the rake faces 3 of the chip removing grooves 2, and end cutting edges are provided on the crossing ridge portions of the gash surfaces 18 and the tip end relief surfaces of the tool body 1 respectively. The chip removing grooves 2 are arranged at unequal intervals in the circumferential direction of the tool, and the end cutting edges are arranged at an equal interval in the circumferential direction of the tool. COPYRIGHT: (C)2008,JPO&INPIT