Tool edge geometry’ and wear’ recognition by using contact method

The aim of this paper is to present a device to measure non-destructively the geometry of cutting edges as well as to detect the wear. This might sound easy. One might propose a usual optical way where an edge is illuminated by an inclined beam and observed from the top. Another might try to use a surface roughness measurement device. However, those were all tested in the past and ended up with a total failure or severe limitation in application. The major reason consists in the size of roundness. For the case of a lancet or shaving knife the roundness is of the order of 2 – 5 µm and varies along the periphery covering over 300 degrees. This paper presents a non-destructive method, which consists of a mechanical device and software package for performing reading and mathematical calculations as well as obtaining practical knowledge on the relationship between the sharpness and performance of various sharp edges according to their purposes