High-pressure coolant is delivered through a duct inside the drill and forced through the center of the gun drill or ejector drill. The coolant provides lubrication and aids in chip removal. Chips exhaust through a V-shaped chip flute along the outside of the drill. Due to the v-groove, the cross section of the tube occupies 3/4 of its circumference.
Gun drills or ejector drills can be used on a variety of machining and turning centers equipped with sufficient high-pressure coolant and filtration systems. These tools and this system allow depth to diameter ratios in excess of 100x’s dia. BTA Heller offers several different carbide grades, coating, and grind options.
BTA Heller sells gun drills in diameter ranges from 0.055″ to 2.0″.