Patent attributes
The present invention relates to a coated cutting tool wherein a ceramic film is formed on a cemented carbide substrate. The substrate is equipped with a ridge line of a cutting edge upon which round honing or combination honing has been performed, a breaker disposed on a rake face connected to the ridge line of the cutting edge, a base face, and an insert hole for securing to a holder. The nose radius is set to at least 1.6 mm. The ceramic film is equipped with an α-type aluminum oxide film. The ten-point average roughness Rz (5 microns reference length) is set to no more than 0.2 microns for the inside of the honed section, the flank face side of the honed section, and the rake face side of the honed section. The ten-point average roughness Rz is set to no more than 0.5 microns for the upper section of the breaker, the base face, and the area around the insert hole.