Compared with single tube system (STS), gun drill system can process smaller holes, but its productivity is lower. The best results can be achieved by using machine tools specially designed for gun drills. Pre-drilling can be used for guidance to improve the gun drilling effect of traditional machine tools.
The cutting fluid is supplied through the whole drill bit, and the chips are discharged along the V-shaped chip groove of the drill bit
Seals are required between the workpiece and the drill sleeve and at the rear of the chip box
The required coolant pressure is about 50% higher than the STS single pipe drill system
High coolant pressure and filtration accuracy of 5 - 10 µ m (0.000196 - 0.000394 inch) are required
Excellent performance in drilling very hard materials and chip breaking difficulties
Able to achieve fine tolerance and ideal surface quality