1/4 X 4" Long Groo-V Tip Multi-Purpose Drill Bit, Relton GRT-4-4

Especially Suited for Drilling Marble, Granite, Porcelain Tile, Hard Metal, Plastic, Wood, Masonry. Percussion or rotary-only, the Groo-V Tip bit makes holes in almost all materials! Engineered for drilling hard materials, this specialized Ram Tip Bit has a serrated carbide tip, which penetrates faster - up to 50% faster than standard masonry bits! Point Diameter: 1/4", Shank Diameter: 1/4", Overall Length: 4", Drilling Depth: 2-1/4". Note: A drill press-supported drill motor is recommended for drilling hard metal. Slow drilling speeds are recommended, and in some cases, marble and granite may not be drillable with carbide tools.