PURPOSE: To improve roughness of finished surfaces and processing accuracy and extend the tool life by coating a blade part with a diamond film of the preset thickness and cutting a part of the diamond film on the blade part to the preset film thickness in a rotary cutting tool of a drill or the like which are mainly manufactured by tungsten carbide based cemented carbide.
CONSTITUTION: A diamond film of the thickness ranging from 10μm to 50μm is formed in the range from the tip of a blade part of a general purpose drill to the point of 10mm away from the tip by employing a microwave plasma method. Then, the diamond film of the circumferential margin part 5 is cut to the thickness of 3-40μm. This constitution sharpens the cutting blade edge, prevents burr generation, and improves roughness of processed surfaces.
TAKEHATA SEIKI
YOSHIDA SHOICHI
SHIMAKURA FUMINORI
HIDANO FUMIHIDE
TAKABAYASHI NOBUTOSHI
