Evaluation of Cutting Edge Sharpness by Transcribing the Edge on Thin Wire

Abstract

The sharpness of cutting edge plays very important role in the performance of cutting tool, especially in precision cutting operation with single-crystalline diamond tool. Though various methods of evaluating the sharpness of cutting edge have been developed in these several decades, the measuring with the accuracy of the order of micron or less could be obtained only by the direct observation of tool through SEM, which is not convenient for practical machining operation. In this study, a relatively simple method with reasonable accuracy is proposed for evaluating cutting edge sharpness : Cutting edge is pressed against a thin wire of soft metal at right angle, and the indentation transcribed on the wire is observed. Two ways of sharpness evaluation can be used : The one is to measure the minimum load required to make a recognizable indentation, and the other is to reproduce the cutting edge cross-section from the contour of the indentation. The cutting edge with the chamfered width of about 0.1 μm can be discriminated by this method.