TBT Deep Hole Drilling Tools, Accessories and Grinding ...
The machine spindle is sealed by the immersion sleeve, or immersion spindle. The cooling lubricant (coolant) is fed inside the tool through one or more holes (or nodule). The coolant and chip mixture is discharged through a longitudinal slot (bead) on the outside of the tool shank. The cutting edge spans the radius of the hole to be drilled.