Ceramic tile deep hole trimming drill bit set, 10 piece set, 1/4 Hex Shank, 8MM grinding aperture, Grinding length 35mm. 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. New technology: brazing process, firmly fixing diamond particles, not easy to fall off, smooth drilling, long service life 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. 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 10PCS