axially and radially relief-ground, provided with rake and clearance angles for the most common materials, 3 cutting edges, straight flutes, with cylindrical shank, suitable for universal, chatter-free and burr-free countersinking and deburring work in one go, large countersinking area, excellent cutting properties and problem-free Chip flow results from the tapered relief on the jacket and rake angle, a sufficient supply of coolant is essential