Excellent Material: Generally, materials with high hardness and good wear resistance such as high-speed steel are used to meet metal cutting needs. Premium Quality: Our glass hole saw with positioning pilot drill is made of high-quality diamond, a solid hardened steel body, and the surface is coated with a nickel-plated coating, which ensures high hardness. Precise Positioning Pilot Drill Design: Each tile hole saw is equipped with a removable positioning pilot drill. The cutting head of the pilot drill bit is also coated with a diamond coating, which makes it sharper and more durable and effectively fixes the bore position of the hole saw so that holes can be cut quickly. Size: Cutting Diameter: 68 mm - Cutting depth: 30 mm - Total length: 70 mm - Triangular shank diameter: 9.5 mm. Cutting depth: 30 mm Sharp and clean holes: These core drill bits with thicker diamond coating make the edge of the groove sharper and can cut precise flat-bottomed holes without splintering on smooth