Two different drill systems are common.
All two systems can produce holes with excellent surface finish, close dimensional tolerance and concentricity.
High pressure pumps supply cutting fluid down the outside of the drill tube, between the drill and the drilled hole.
The drill shank itself is hollow, and the fluid pressure flushes the chips into the drill body through chiprooms in the drill head, and back out through the drill tube.
The high cutting fluid pressure makes the STS-system more reliable than the Ejector system especially when drilling materials where good chipbreaking is difficult to obtain, i.e. low carbon steels and stainless.
Cutting fluid is pumped down the drill between the two tubes, i.e. entirely within the drill body rather than externally, and the chips are flushed back out through the inner one, also within the drill body. This self-contained system requires less fluid pressure than the STS system and can usually be installed in conventional machine tools without major reconstruction.
STS Drill Tubes
BTA / STS Single Tube System Drill Tubes are available in custom lengths and threaded to customer specs.
DTS Drill Tubes
Ejector / DTS Double Tube System Inner and Outer Drill Tubes are available in custom lengths and threaded to customer specs.
Drill Tube Thread Adapter
Drill Tube Thread Adapters available.
Pressure Heads are available.