These high quality long-lasting durable Diamond Drill Bits are designed for use by D-I-Yers, contractors and hobbyists on very hard or fragile materials such as porcelain tile, ceramic tile, stone, ceramics and glass. Bastex Diamond Drill Bits are premium specialty drill bits designed for drilling in hard abrasive non-ferrous materials. The electroplate bonded diamond drill bits have a superior design developed through extensive testing. Water or oil is recommended for lubrication while drilling due to intensive heat which can damage material and bits without cooling lubrication. Designed for drilling to depths of about ½". (Not for use on metals, concrete, masonry, or with impact hammer drills). Bastex Diamond drill bits are designed to be an inexpensive solution to cleanly and quickly drill in hard and fragile materials where no carbide drill bit is able.Be advised damage may occur to bit or material if a lubricating cooling agent is not used. Package Includes: 3 Diamond Hole Saw Bits 6 mm", 8 mm", 10 mm"