Specification Brand : NACX BulletPoint1 : Product Name: Dry Diamond Drill Bits; Diameter: 8mm / 0.31”; Hex Shank: 6.35mm/ 1/4”; Total Length: 80mm / 3.15”. BulletPoint2 : Made of high carbon steel and brazed diamond , for ordinary diamond hole opener, the durability of this brazing hole opener, high temperature resistance, use range and other effects are greatly increased. BulletPoint3 : Drill bits are 1/4” hex shank design that is more suitable for electric drill chuck,not easy to slip when working,improve work efficiency. BulletPoint4 : Dry diamond drill bits built-in wax lubricant that can melt and cool the cutting surface during dry drilling, effectively reduce the temperature lubrication protection drill bit. BulletPoint5 : Dry diamond drill bits is able to drill clean holes in all types of tiles, perfect for porcelain, granite, ceramic, glass, marble, stone, masonry brick. BulletPoint6 : No core bits included, just the water ring with black rubber gasket installed. Color : Blue CuttingAngleString : 90.0 degrees ExternallyAssignedProductIdentifier1 : 0751314442924 ExternallyAssignedProductIdentifier2 : 751314442924 FinishType : Black IncludedComponents : 3 Pcs Dry Diamond Drill Bits ItemName : NACX 8mm Dry Diamond Drill Bits, 1/4 Hex Shank Brazed Diamond Core Drill Bits for Granite Marble Porcelain Tile Ceramic Stone Glass Hard Materials, 3Pcs ItemPackageDimensions_Height : 13 centimeters ItemPackageDimensions_Length : 9 centimeters ItemPackageDimensions_Width : 1.8 centimeters ItemPackageQuantity : 1 ItemShape : Round ItemTypeKeyword : core-drill-bits Manufacturer : NACX Material : High Carbon Steel ModelNumber : Water Ring AZ NumberOfFlutes : 2 NumberOfItems : 1 NumberOfPieces : 1 PartNumber : 1 ProductDescription : Feature: Brazing process sintering, high temperature resistance, high hardness, durable. Dry diamond drill bits are sharp and durable, cutting perfect clean smooth holes. Dry diamond drill bits compatible with most hand-held drill, drill press. In order to improve the service life of the drill, it is recommended to open the small moon pressure groove on the item at a 45 degrees angle during the whole high-speed process, and then slowly erect the drill to 90 degrees. Scope of use: glass, ceramic, marble, concrete, vitrified brick, granite, quartz stone, full ceramic tile.