Abstract: Disclosed herein is a cutting tool having high toughness and abrasion resistance, in which a coated cutting tool including a cemented carbide substrate, a cermet substrate or a ceramic substrate coated with a hard coating film by means of chemical vapor deposition, moderate temperature-chemical vapor deposition or physical vapor deposition, and/or a cemented carbide cutting tool, a cermet cutting tool or a ceramic cutting tool are subjected to wet blasting using 10-300 ?m sized particles to decrease residual tensile stress or increase residual compressive stress, thereby improving toughness, and also, reducing surface roughness of the cutting tool, thus remarkably increasing chipping resistance and flaking resistance.

Abstract: A cutting insert is disclosed, where the shape of a cutting edge is improved so that the minimum cutting load is applied during a cutting process to obtain the same surface roughness although the cutting insert is fed at high speed and to thus obtain high efficiency and high productivity. The diamond-shaped cutting insert includes an upper part and a lower part, a top surface and a bottom surface that are lower than the upper part and higher than the lower part, respectively, side parts for connecting the top surface to the bottom surface, corner parts for smoothly connecting the side parts to each other, a cutting edge formed by crossing the top surface, the bottom surface, the side parts, and the corner parts, and a chip breaker formed from the cutting edge to between the top surface and the bottom surface.