Special features The DRYGRES PREMIUM range of diamond drill bits is perfect for drilling all types of tiles, especially porcelain stoneware, and other stony materials such as marble and granite. RUBI has used VACUUM BRAZED technology in the DRYGRES PREMIUM range of drill bits, which allows them to withstand higher temperatures due to friction. This results in a longer service life for the diamond drill bits. DRYGRES PREMIUM diamond drill bits, with diameters from Ø 6 to 12 mm, are perfect for attaching bathroom accessories or any type of decorative accessory to tiled surfaces. The other diameters of the DRYGRES PREMIUM diamond drill bit range, from Ø 20 to 85 mm, are primarily designed to offer tilers the best results when drilling for sockets, pipes, drains, lighting, etc. DRYGRES PREMIUM diamond drill bits are dry ground and, thanks to their M14 threaded connection, can be used directly with an angle grinder or, via an adapter (ref. 05976), with a drill – without impact function. The average lifespan of DRYGRES PREMIUM diamond drill bits varies depending on the diameter: those from Ø 6 to 12 mm have an average lifespan of 60 holes, and for drill bits from Ø 20 to 85 mm, this is 150 holes. The average lifespan of the drill bits ALWAYS depends on the type of material, its thickness, and proper cooling and use. The drilling depth of DRYGRES PREMIUM diamond drill bits is 30 mm for drill bits from Ø 6 to 35 mm and 38 mm for drill bits from Ø 43 to 85 mm. In diameters Ø 6, 8, 10, and 12 mm, the PREMIUM DRYGRES contain wax inside. This wax melts during use of the drill bit, facilitating cooling and evacuation of drilling debris (If the wax runs out, the drill bit can still be used. Only the total loss of diamond indicates the end of the drill bit's life). DRYGRES PREMIUM diamond drill bits (diameters Ø 20 to 85 mm) have a side opening that improves cooling of the drill bit and makes it easier for us to remove the core after each hole. Before drilling a new hole, we must ensure that the drill bit is clean. Drill bits from Ø 43 mm are segmented to improve stability during drilling. The maximum operating speed for DRYGRES PREMIUM diamond drill bits is 14,000 rpm. For a better finish and a longer lifespan of the drill bit, it is important to observe the correct speed and to make a slight oscillating movement during drilling.