【Diamond Hole Drill Bit Size】Dry diamond core drill bits kit size included:10pc-6mm hole diameter drill bits with 1/4 Hex Shank,length is 65mm. 【Dry Drilling Design】Diamond drill bits built-in wax lubricant that can melt and cool the cutting surface during dry drilling,you can also use water as an additional coolant to extend the life of the drill bits. 【Wide Application】Diamond hole saw set have wide application,you can use them to drill holes for your ceramic pots,also can use in different hard material such as:Granite,Tile,Glass,Marble,Brick,Stone,etc. 【1/4 Hex Shank】Drill bits are hex shank design that is more suitable for electric drill chuck,not easy to slip when working,improve work efficiency. 【Friendly Reminder】In order to improve the service life of the drill,it is recommended to open the small moon pressure groove on the item at a 45 degree Angle during the whole high-speed process, and then slowly erect the drill to 90 degrees Diamond Drill Bits,NOEAIKE 10-Pack 1/4"(6mm) Dry Diamond Core Drill Bit Set for Ceramic,Granite,Tile,Glass,Marble,Brick,Stone with 1/4 Hex Shank