... tile drilling. The latest glass-and-tile bits have a spear-pointed carbide tip to reduce breakout. Available in seven sizes ... /16" (8mm), 3/8" (10mm) and 1/2" (12mm), these spear bits provide smooth, accurate drilling in ceramic tile, marble, mirrors ... goal - so don't hesitate to contact us! Export OEM High Quality Carbide Glass and Tile Drill Bit