7 SizesThe drill bit set has 7 different sizes: 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm.These glass drill bits are ideal for various drilling tasks, with high drilling precision, and can be installed on electric drills. High-quality materials Made of carbide head materials, low strength, high hardness, improve work efficiency and can maintain longer cutting time than ordinary steel drill bits.U-shaped groove and triangular handle The U-shaped spiral is smooth and flat, and the drilling is smoother.The triangular shaft design makes the clamp tighter without slipping. Spear Tip DesignThis sturdy tungsten carbide tip drill is sharp, easy to locate, stable drilling, fast, does not cross the limit, and the opening is neat and smooth. Widely usedThe drill bit set is suitable for drilling ceramic tiles, concrete, ceramic tiles, bricks, wood, plastic, glass, masonry and other materials.It is widely used in home decoration, manual DIY and other scenes.