INDEXABLE DRILL WITH IMPROVED CHIP FLUTE FOR SMOOTHLY DISCHARGING CHIPS BY INCREASING BREADTH OF CHIP FLUTE GRADUALLY

摘要

PURPOSE: An indexable drill with an improved chip flute is provided to easily discharge chips by increasing the breadth of the chip flute gradually. CONSTITUTION: In an indexable drill including a shaft unit(110) and a shank unit(120), a flute(130) is formed at the shank unit, and discharges chips. An insert mounting groove is formed at the front end of the shank unit. An insert is mounted to the insert mounting groove. The center and the front end of the flute are larger than the lower center of the flute in sectional area. An oil hole is formed at the center of the shank unit. Two oil holes are formed along the flute. The ratio of the lower center to the center and the front end of the flute in sectional area is 1: 1.05 to 1.3: 1.02 to 1.2. Thereby, chips are smoothly discharged through the flute.