5/16 in Diamond Drill Bit 5/16 inch 3 Pack for Porcelain Tile Drill Bit Glass Drill Bit Diamond Tip Bit with Core Guide to Hold in Place and Prevent Jumping 8mm Porcelain Drill Bit for Ceramic Tile 8mm 5/16” PORCELAIN DRILL GUIDE – Using The Drill Bit Guides Makes A Cleaner Hole As You Don’t Need To Start The Diamond Drill Bit At An Angle So You Don’t Get An Oval Shaped Hole. Guide May Be Tight To Start So You Can Drill Out The Guide With Bit Either Before Taping Guide To Wall Or After As Long As Tape Is Very Secure. Guides Are Designed So You Can Snap Them Into Pieces For Places Where Its Too Tight To Use Whole Guide, You Can Drill A Hole Using Just A Quarter Of Guide If Held Down Correctly. STARTING 5/16 DIAMOND BIT –These 5/16 Inch Tile Drill Bits Are 5/16 Diamond Core Bits So There Is No Point At The End, If You Try And Drill Straight It Will Just Spin Around. There Are 3 Ways To Use Them 1st In A Drill Press, 2nd Start At An Angle Until You Grind A Half Moon Shape, This Will Be Enough Of A Groove To Hold The Bit Steady While You Gradually Bring The Bit To The Upright Position. 3rd With Tile Drill Guides We Include With The Bit. Tape Guide Securely To Tile And Drill Straight. COOLING 5/16 DIAMOND TIP DRILL BIT – We Use Largest Diamond Grit On Our 5/16 Ceramic Tile Drills, They Cut Better And Last Longer But Because They Are Larger They Get Hotter So Keeping The Tip Cool Is Critical. If The Tip Is Allowed To Get Extremely Hot The Weld Between The Diamonds And Steel Melts And The Diamonds Will Fall Off In The Hole, So Unless Flushed Out Diamonds Grind Against Diamonds Small Bits Have A Huge Heat Build Up At The Tip So This Is What Needs Cooled Not Spraying Onto Side. 5/16” TILE DRILL BIT - Fit Regular Drill, This Type Of 5/16 in Diamond Core Drill Bit For Porcelain Tile Must Be Kept Cool And Wet, Dip Tile Drill In Cold Water Every 5-10 Seconds, Also Put Water In Hole To Cool Material Down - If You Do Not Do This The 5/16 Inch Diamond Tip Drill Bit Will Not Get Dozens Of Holes, You Will Only Get 1 Hole. There Are No Teeth On These 5/16 Diamond Bits Just Diamond Grit So You Are Grinding A Hole Not Drilling So A Lot Of Heat Is Generated When Grinding Porcelain. 5/16 IN GLASS DRILL BIT – These Bits Can Drill Glass Ceramic Porcelain Or Granite. To Extend The Life Keep The Cutting Face Cool At All Times And The Material Cool By Forcing Water Into The Hole With A Wet Sponge Or Spray Bottle, Remember Spraying Water Onto The Side Of the 5/16 Bit Only Cools The Side Of the Bit And Not The Hot Cutting Edge. You Must Remove The Debris Or Plug From Inside The 5/16 Diamond Glass Drill Bit As You Go Or It Will Build Up inside And Prevent The Drill From Working. UPC 799964003973 ASIN B09Y67DQ7J Brand Name The Amazing Tile And Glass Cutter Shank Type Round Unit Count 1.0 Count Item Weight 1 Ounces Part Number HOLEDMD08X3 Point Style Diamond Point Finish Types Diamond Manufacturer The Amazing Tile And Glass Cutter Material Type Diamond Item Dimensions 1.97 x 0.31 x 0.31 inches Tool Flute Type Straight Cutting Diameter 0.31 Inches Number of Flutes 3 Included Components 3 x 5/16 (8mm) Diamond Drill Bits Surface Recommendation Ceramic,Glass,Porcelain,Stone