Drilax Diamond Drill - Hole Saw Set of 10 Pieces All Popular Sizes from 1/4 '' to 2 '' Inch for Wet division Tiles, Glass, Fish Tanks, Marble, Granite, instrumentation, Porcelain, Bottles, Quartz Sinks, Lot 10 Diamond Coated Core Hole Saws - Kitchen, Bathroom, Shower, Faucets 10 Popular Sizes : 1/4 '' to 2 '' - soigne storage case. piercing character Diamond Drilling Tool of 10 various Sizes : 1/4 '', 3/8 '', 1/2 '', 3/4 '', 1 '', 1 1/4 '', 1 3/8 '', 1 1/2 '', 1 3/4 '', 2 '' Popular 10 Sizes - peachy Value No need for Center Pilot Drills Please Do NOT Use Dry Maximum 3/8 inch Shank Size Can be used with hand-held or Upright Drillers The diamond particule coating on DRILAX hole saws give patronizing performance and lifetime. Please our tools do not need center pilot holes. Center pilot hole drills are mostly for wood, , etc.. Drilax tools can 1 '' in depth. Electroplated diamond coating will off if the tool gets too violent. Never your drill bit run thirsty. Here how you could use water to keep the tool unfriendly : a - You can build a mini water dam around the hole with plumbers putty. b - You can to spray water on the drill bit. c - Or you can running water to unfriendly the drill bit. easy TO USE Center pilot drill bits are for wood, metal, etc. ; Here how you can keep the drill bit on target : a - You can make your personal guide out of plywood - moldable or even a card board. All you need to keep the drill bit in place until it makes the letter marks. b - You can drilling at an angle, with the edge of the drill bit making a C slot and then getting the drill bit up to upright. c - You can manually the drill bit with sweaty sponge. Please tutelary gear. Amazon DRILAX Diamond Hole Saw Guides .