Product DescriptionDiamond Drill Bits for Tiles, Stoneware, Ceramics, MarbleDetailsFour diamond drill bits Diameter: 6 mm, 8 mm ,10 mmand 12mm Length 67 mm / Diamond grit 10 mm Practical and robust storage box included in delivery Hexagonal shaft with 1/4 diameterFor drilling clean holes in glass, tiles and ceramic, porcelain, granite, marble, quartz, limestone, fiberglass, terrazzo, porcelain stoneware, masonry and sandstone hard tiles.Quality diamond drill bits Professional Reliable and universally compatible SR diamond drill bits are set with a high quality, temperature resistant diamond grit.This allows drilling in hard materials such as granite or marble tile.The 1/4 inch diameter hex shaft is suitable for t screwdrivers and light hammer drills such as Bosch, Hilti, Metabo, Milwaukee, and others heat and robust A coolant wax filling reduces heat generation when drilling. dry. For longer life, we recommend cooling the drills with water or another suitable coolant.Read moreDesigned for heavy duty use How to use 1.) Pre-drilling: place the drill bit at an angle of approximately 30 until until a notch has formed at the the place where the tip is lodged. 2.) Straighten the bit, increase the number of revolutions (max speed) and complete a rotary movement. Continue to drill at 3.) Add water or suitable refrigerant. or raised the drill from time to time so that it can cool down. CAUTION: Not for use on Concrete or Masonry