SUTTON TOOLS® D604-Series Glass & Tile Drill Bits are designed for smooth drilling in up to Class-3 Ceramic Tiles and Glass but can also be used for drilling brick, plastics and fibreglass. Their unique design features a specialised Tungsten Carbide Tip (TCT) with Spiral Flutes which makes these drill bits last up to 7X longer and cut 30% faster than traditional glass & tile bits. NOTE: These bits are not suitable for drilling toughened glass. Features 4-Facet Diamond Spear point Design - Shaves rather than cuts for improved precision and penetration, Stronger Carbide Tip with Copper Brazing - Provides better heat resistance giving up to 7X longer life, Spiral Flutes - Aids dust extraction and reduces heat build-up for 30% faster drilling, Longer Overall Length - Permits deeper drilling than standard glass & tile bits, Cylindrical Shank - Suits non-hammer action portable power drills, Specifications Diameter: 8.0 mm, Overall Length: 100 mm,