Patent ID: 7732066

Claim:
A router cutter consisting of: a machining tool shank having a blade portion of 3.175 mm or less diameter, the blade portion fabricated from a cemented-carbide base material containing tungsten carbide and cobalt, with the cobalt inclusion amount being 4 weight % or more and 12 weight % or less; and coated to a given thickness in a single layer over said cemented-carbide base material, a compound thin film made up of a combination of, in given elemental proportions, one or more elements selected from the group, chromium, vanadium, silicon and aluminum, and one or more elements selected from carbon and nitrogen; wherein said compound thin film is vapor-deposited onto said base material under reaction-gas pressure, base-material bias voltage, and deposition-temperature conditions that, together with said given thickness and said given elemental proportions, are predetermined so as to impart a compressive residual stress of 0.1 GPa or more and 8 GPa or less to said compound thin film, said compound thin film has a surface roughness of 0.01 μm or more and less than 0.3 μm by indication Ra, and said predetermined thickness of said compound thin film is 0.05 μm or more and less than 1.5 μm.