QUALITY MATERIAL - Tungsten carbide tipped cutter and anti-rust electroplated steel drill bit body, built for faster penetrating, prolonged life and heavy-duty use. PROFESSIONAL lDESIGN - Spear-shaped design will effectively reduce breakout. Hex shank shank allows for stable holing and quick release in power drill. 1/4" hex shank design for quick release. MULTIPLE PURPOSE - These masonry drill bits can easily penetrate tile, terracotta, concrete, cement, ceramic brick, glass, plastic, cinderblock, wood and many more. Please try to keep the drill vertical and use water or coolant for lubrication when drilling. Don't use these bits to drill hard tile. 10PC BITS SET - The set includes 10 tile and glass drill bits of 5 most-commonly used sizes, including 1/8", 3/16", 1/4", 5/16" and 3/8". They are well packed in a plastic case for easy storage and transportation. SATISFACTION GUARANTEED - We do care about your satisfaction. We try our best to ensure each product is in perfect condition before you get it, but if something is not up to your satisfaction, please contact us. masonry drill bits