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 accuracy, and can be installed on drilling machineselectric. High Quality MaterialsMade 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 handleThe 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 heavy-duty tungsten carbide tip drill is sharp, easy to locate, stable drilling, fast, does not break through the boundary, and the opening is sharp and smooth. Widely UsedThe drill set is suitable for drilling ceramic tile, concrete, ceramic tile, brick, wood, plastic, glass, masonry and other materials. It is widely used in the decoration ofHome, manual DIY and other scenes. Tungsten carbide tip Excellent chip evacuation and smooth cut, high hardness, sharpness and durability. U-groove design The spiral chip evacuation design, combined with the rapid evacuation of drill chips, makes the work more efficient. Non-slip triangular handle Triangular handle design, the handle allows the bit to be firmly fixed in the electric drill.