Widely Use--Carbide Triangular Drill bit mainly used to provide accurate positioning for diamond bit Machine --Suitable for any electric drill,hand drill,Bench Drill, When use Angle Grinder,please install angle grinder drill chuck，Recommend RPM: 2000-5000.The faster the better(Cannot be used on machines below 2000 rpm). When you are building/remodeling a bathroom or kitchen like installing shower or install the faucet and handles in bathroom, you will need to drill holes through Porcelain tiles without cracking them, so you could use our diamond tip drill bit to make those holes very precise This tile hole cutter adds wax lubricant inside. During drilling, the wax will melt to cool the cutting surface, add additional water can prolong the working life of the bit and to remove the debris during the drilling process. This porcelain tile drill bit Creates a high precision, you could drill smoothly with no broken edges,Using this bit in an angle grinder will like a hot knife through butter For a better finish and longer duration of the tile hole saw,you could start on a slight angle to get through the top finished surface, then with light pressure carefully work through the tile. The average life of the porcelain tile drill bit depends on several factors,including the type of aggregate and material, its thickness/hardness ,proper cooling and use Package includes: 20pcs 1/4 Inch 6mm. Supplied in square plastic box Quality Creates Better Life. All our products are subjected to strict quality tests. We want all the products can be recognized for their quality and durability.