The drilling depth of the DRYGRES 4DRILL is 36 mm for the diameters 6, 8 and 10 mm, and 40 mm for the diameters 12, 14 and 20 mm. All DRYGRES 4DRILL burs have a wax inside. The wax melts with the use of the drill bit and improves cooling and removal of drilling debris. When the wax runs out, the drill can continue to work. Only complete wear of the diamond indicates the end of drill life