• DRYGRES 4DRILL diamond drill bits are designed for use with electric drills. • Hexagonal connection of drill bits with 13 mm head. • 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 bits have a wax inside. • The wax melts with the use of the drill bit and improves cooling and removal of drilling debris. • When dry drilling it is important to cool the drill bit properly so make continuous and circular movements with the drill. This improves airflow around the drill bit.