Able to drill into a range of materials including tiles, porcelain, ceramics and non-toughened glass. Blade tips manufactured from high quality YG6X tungsten carbide for a prolonged life. Carbon steel hex shank ensures anti-slip tight fit into electric, hand and bench drills. Spear tip shape for precise alignment. Designed to fit any standard sized drill chuck. Contents: Ø3-10mm in 1mm increments.