BGTEC 9pcs Dry Diamond Core Drill Bits Set for Porcelain Tile Ceramic Marble Brick with M14 Thread Diameter Mixed 6/8/10/12/20/35/45/68mm 1pc Hex Backer

【✅SIZE 7】5pcs/box: Diameter (6/8/10/12/20/35/45/68mm wIth 1pc M14 Hex Backer), Diamond height 10mm, Tottal length：65mm，Diamond grit: #35/40; 【✅Application】For dry or wet drilling of porcelain tiles, granite, marble, stone; smooth drilling without breakage; 【✅Special Design】U-shaped groove design allows diamond drill bits to dissipate heat and chips faster, effectively improving drilling efficiency and better performance； 【✅Longer Service Life】High quality diamond particles and vacuum brazing technology make the drill bit harder and provide longer working life. It can be dry drilled without water, but using water will prolong the life even more; 【✅Machine:】Anger grinder. lf you want to use electric drill or other machines, you can use SDS or Hex Shank Adapter. Recommended speed 6000RPM, maximum speed 11000RPM.