<b>High Rigidity Diamond</b><p> This tile hole saw are made of industrial grade carbon steel with nickel-plated coated body that resist corrosion. Thicken corundum coating on the tops offers superior cutting strength for maximum drilling outcomes.<p> <b>Extraordinarily Sharp</b><p> Each hole saw drill bit was processed by a smooth and exact finish that lower the incision resistance and drill pressure, increase the sharpness and the use of water lubrication. Excellent for making clean and precise hole on glass or ceramic and considerably extending drill bit life.<p> <b>Large Clearance Hole</b><p> These ceramic drill bits along with large clearance hole facilitate the entrance of cooling water and escape of chips. Making the drilling process more easy and relax.<p> <b>Widely Application</b><p> There are 15 different sizes included with this glass drill set to meet various demands. Perfect for drilling glass, tile bottles, blocks jars, fiber glass porcelain tile ceramic, vitrified, brick and stone. <p> <b>15 Sizes</b><p> Each drill bit set includes: 0.24", 0.32", 0.4", 0.48", 0.55",0.63", 0.11", 0.79", 0.87", 0.98", 1.02",1.11", 1.18", 1.57", 1.97"<p> Total length: about 2".<p> <b>Package Contains</b><p> 15Pcs* Diamond Coated Drill Bit<p> <b>Attention:</b><p> Please keep the speed within 800-1000 per minute, low drill pressure and increased use of water lubrication will extend drill bit life.<br> And please keep adding water when the diamond drill bits are working on the glass or ceramics.<p>