High Quality: The drill bit is made of professional alloy steel. High hardness, strong and durable. It has good wear resistance and can be used longer than ordinary steel drill bits. The hexagonal shank allows for stable holding and quick release in the electric drill. Dimension: 10pcs drill bits set with 7 different sizes: 1/8? (3mm), 5/32? (4mm), 3/16? (5mm), 1/4? (6mm), 5/16? (8mm), 3/8? (10mm), 1/2? (12mm) to meet your different needs. Four-corner sharp chamfer design, easy and stable positioning, faster drilling speed, better stability, low fluctuation frequency and high efficiency. Application: Ideal for drilling ceramic tiles, glass, marble and mirrors. When drilling hard materials, please use water for lubrication, good cooling can extend the life of the drill bit. Please try to keep the drill vertical and use water or coolant for lubrication when drilling. Do not use these drill bits to drill hard tiles. Tungsten Carbide Tip: The bit features a tungsten carbide tip for efficiency and extended life. Professional quality alloy steel - Smooth and precise drilling in ceramic tiles, marble, mirrors, glass, aluminum, concrete, and wood. For DIY and interior design enthusiasts, this is also an essential tool for drilling glass and other hard and fragile work surfaces.