PURPOSE: To improve adhesion and film characteristics, to provide excellent wear resistance, to improve discharge ability of chips, to prevent the occurrence of chips, and to perform industrial and efficiency.
CONSTITUTION: In manufacture of a rigid film-coated twist drill wherein at least the drill margin part of a cutting edge part is covered with a rigid film, after the part, corresponding to drill machining operation, of a parent material surface in the shape of a round bar formed of a high speed steel tool is covered with a rigid film consisting of a carbide, nitride, or carbonitride, containing two or more kinds of metallic elements through an arc discharge type ion plating method, by cutting machining or grinding machining at least a part equivalent to a drill groove, a drill groove wherein a drill parent material skin surface is exposed is formed.
YAMANA KAZUO
YAMADA YASUYUKI
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