Diamond Drill Bit - Hole Saw Set of 10 Pieces All Popular Sizes from 6mm to 50mm for Wet Cutting Tiles, Glass, Fish Tanks, Marble, Granite, Ceramic, Porcelain, Bottles, Quartz Sinks, Lot 10 Diamond Coated Core Hole Saws- Kitchen, Bathroom, Shower, Faucets Quality Diamond Drilling Tool Set of 10 Different Sizes: 6mm,8mm,10mm,14mm, 6mm,18mm,22mm,35mm,40mm,50mm

✔No need for Center Pilot Drills
✔Please Do NOT Use Dry,keep watering while drilling
✔Lower pressure 
✔Lower drill speed (RPM≤1000)

Please note our tools do not need center pilot holes. Center pilot hole drills are mostly for wood, metal, etc
★Tip: EASY TO USE
Here is how you can keep the drill bit on target:
(1)You can start drilling at an angle, with the edge of the drill bit making a C slot at the angle of 45°and then getting the drill bit up to vertical
(2)You can manually guide the drill bit with wet sponge
(3)You can make your own guide out of plywood - plastic or even a card board. All you need is to keep the drill bit in place until it makes the initial marks
★Tip： How to keep the tool cool
Electroplated diamond coating will wear off if the tool gets too hot. Never let your drill bit run dry
Here is how you could use water to keep the tool cool:
a- You can build a mini water dam around the hole with plumbers putty
b- You can choose to spray water on the drill bit
c- You can use running water to cool the drill bit

★Package content:
1 x Tacklife Diamond Drill Bits
1 x Kraft Paper Package
1 x User Manual
1 x 24 month Warranty