Indexable cutting tool inserts and methods of using indexable cutting tool inserts

A machining method comprising removing material from a workpiece with at least one cutting tool insert secured to a tool holder of a machine tool, wherein the cutting tool insert comprises:

• a first end including a circular periphery, the circular periphery defining at least two arcuate cutting edge regions;
• a second end;
• and
• an elongate portion extending from the first end to the second end along a longitudinal axis of the cutting tool insert, the elongate portion comprising:
• a mounting region extending along a first portion of the longitudinal axis to the second end, the mounting region comprising a plurality of substantially flat side regions capable to be received in an insert pocket of a tool holder and defining a corresponding plurality of discrete indexing orientations of the cutting tool insert as installed in the insert pocket of the tool holder;
• wherein the mounting region extends along at least 10% of an overall longitudinal axial length of the cutting tool insert, and wherein the substantially flat side regions are circumferentially distributed about the longitudinal axis such that each indexing orientation is defined by a unique pair of substantially flat side regions;
• and
• an inverted frustoconical shaped clearance region extending along a second portion of the longitudinal axis to the circular periphery of the first end, wherein each arcuate cutting edge region of the circular periphery is associated with exactly one of the plurality of indexing orientations, such that when the cutting tool insert is installed in a given indexing orientation, only the arcuate cutting edge region corresponding to that indexing orientation is positioned for engagement with the workpiece.

A tool holder including at least one replaceable cutting tool insert, the cutting tool insert comprising:

• a first end including a circular periphery, the circular periphery defining at least two arcuate cutting edge regions;
• a second end;
• and
• an elongate portion extending from the first end to the second end along a longitudinal axis of the cutting tool insert, the elongate portion comprising:
• a mounting region extending along a first portion of the longitudinal axis to the second end, the mounting region comprising a plurality of substantially flat side regions capable to be received in an insert pocket of a tool holder and defining a corresponding plurality of discrete indexing orientations of the cutting tool insert as installed in the insert pocket of the tool holder;
• wherein the mounting region extends along at least 10% of an overall longitudinal axial length of the cutting tool insert, and wherein the substantially flat side regions are circumferentially distributed about the longitudinal axis such that each indexing orientation is defined by a unique pair of substantially flat side regions;
• and
• an inverted frustoconical shaped clearance region extending along a second portion of the longitudinal axis to the circular periphery of the first end, wherein each arcuate cutting edge region of the circular periphery is associated with exactly one of the plurality of indexing orientations, such that when the cutting tool insert is installed in a given indexing orientation, only the arcuate cutting edge region corresponding to that indexing orientation is positioned for engagement with a workpiece.