Patent ID: 7765902

Claim:
A cutting tool for high-quality high-efficiency machining of which portions involved in cutting comprise hard members, said cutting tool including a finishing cutting edge which is first cut into a workpiece, and superfinishing cutting edges for finishing the workpiece following the finishing cutting edge, wherein said superfinishing cutting edges project from said finishing cutting edge in such a direction that the depth of cut increases, and each include a burnishing portion having a predetermined width in the feed direction of the tool, and a wiper portion extending from said finishing cutting edge to said burnishing portion, whereby said superfinishing cutting edges burnish a finished surface of the workpiece, while removing a affected layer formed on the finished surface by said finishing cutting edge, and wherein said finishing cutting edge and said superfinishing cutting edges have chamfers for strengthening the respective cutting edges, the chamfers of said superfinishing cutting edges having a width W 2 that is smaller than the width W 1 of the chamfer of said finishing cutting edge.