CUTTING TOOL INSERT AND CUTTING TOOL INSERT HOLDER

摘要

PROBLEM TO BE SOLVED: To provide a cutting tool insert and a cutting tool insert holder to be used in machining of a workpiece.SOLUTION: An insert (2) includes eight identical cutting edges (14). Each independent cutting edge (14) has a first cutting edge portion (16) and a second cutting edge portion (18). A corner angle between the first cutting edge portion (16) and the second cutting edge portion (18) is within the range of 75-90°. The first cutting edge portion (16) and the second cutting edge portion (18) have substantially the same length to provide a substantially equal cutting. As seen along a center axis (4), a first angle (&bgr;) within the range of 14±9° is formed between a first imaginary line extending from the center axis (4) to a corner point at a first side surface (8) and a second imaginary line extending from the center axis (4) to one adjacent corner point (24) at a second side surface (10).