What System is Best for You?
The characteristic of the single flute gundrilling process is that coolant is fed through the coolant hole in the tool and exits along with the chips in the V-shaped groove (flute) on the drill tube from the drilled hole. The coolant also provides lubrication to the drill periphery.
This is possible if coolant, i.e. deep-hole drilling oil or emulsion (min. 10 – 12% concentration, with additives), is provided in sufficient quantity and pressure.
BTA – System
The BTA-System is a deep hole drilling system for special deep hole drilling machines with an external coolant supply and an internal chip removal (single tube system). Necessary for suppling the coolant to the workpiece and for sealing off the process on workpiece and boring bar, requires the BTA-System a pressure head (BOZA).
This system is used for bore hole diameters between 7,76 mm and 700 mm and enables hole depths over 100 x D. As from dia. 18 mm the tools mainly become indexable cutting inserts and guide pads.
Ejector – System
The Ejector-System is a variation of the BTA-System which is applied for conventional machine tools and machining centers. The coolant is introduced via an annular space between the boring bar and an inner tube (double tube system). The coolant exits at the side of the drill head, flows around it and back out inside the inner tube together with the chips. A sealing on the workpiece is not necessary.
This system is used for bore hole diameters between 18,40 mm and 200 mm and enables hole depths over 100 x D. As from 18 mm the tools mainly become indexable cutting inserts and guide pads.