CUTTING TIP REPLACEMENT TYPE ROTARY TOOL

摘要

Provided is a tip replacement type rotary tool in which the cutting resistance can be reduced while maintaining a high chipping resistance of a main cutting edge formed on an insert and which is suitable for a highly efficient high-feed cutting. A tip replacement type rotary tool has an insert which is detachably attached to a rotary tool body and which is in the form of a polygonal planar plate or a circular plate in a plan view. The insert is provided with a negative honing and a land, on a rake surface of a main cutting edge of the insert, and a round corner cutter on a corner portion of the insert. When the insert is attached to the rotary tool body, the main cutting edge of the insert defines the lowermost point in the rotation axis direction of the rotary tool body, and the width of the negative honing or the widths of the negative honing and the land are gradually increased from the lowermost point toward the outer peripheral side direction with respect to the rotation axis direction of the rotary tool body, whereby the cutting resistance can be reduced while maintaining a high chipping resistance of the main cutting edge.