Diamond Drill Bits for Tiles, Stoneware, Ceramics, Marble Four diamond drill bits: 5 mm, 6 mm, 8 mm, and 10 mm diameter; 67 mm length; diamond grit 10 mm Includes practical and robust storage box Hexagonal shaft with 1/4" diameter For drilling clean holes in glass, tiles, ceramic, porcelain, granite, marble, quartz, limestone, fiberglass, terrazzo, porcelain stoneware, masonry, and sandstone High-quality, temperature-resistant diamond grit for reliable performance on hard materials 1/4 inch hex shaft compatible with screwdrivers and light hammer drills from Bosch, Hilti, Metabo, Milwaukee, and others Coolant wax filling helps reduce heat during drilling For extended bit life, use with water or a suitable coolant Designed for heavy-duty applications How to Use: 1. Pre-drill: Place the drill bit at a 30-degree angle to create a notch at the desired drilling point 2. Straighten the bit, increase speed to maximum, and apply steady rotary motion 3. Use water or a suitable coolant, or periodically withdraw the bit to allow cooling CAUTION: Not intended for use on concrete or masonry