5 Piece High Durable Fine Grain Drill Bits in 4 Different Sizes: Including 2 x 6mm (1/4 ''), 1 x 8mm (5 / 40.6cm), 1 x 10mm (3/8 cm), 1 x 12mm (1 / 5.1cm), to meet your different needs. & nbsp; Material: Made from high quality tungsten carbide and carbide with reinforced head, its hardness is higher than ordinary drill bit which prevents its cracking and prolongs its service life and heavy use. resistance and wear resistance. & nbsp; Special Design: U-type housing with a rapid drill dust removing design, 3-flats shank allows a drill bit to be held firmly and stably while drilling. Triangular spear tip triggers hike and glide of the drill. High efficiency spiral, smooth and flat surface make drilling smoother. Superior Performance: This tungsten carbide tip drill set is sharp, can be effective in removing residue, and can improve your working efficiency. Drill holes are clean, smooth and free of edges broken that do not cause shocks, the easy positioning improves opening speed and facilitates removal. Perfect for drilling in all kinds of materials including concrete, tile, brick, wood, plastic, soft metal, masonry, and more. Note: When drilling rigid material (glass, porcelain, ceramic tile marble or granite), please use water for lubrication. Functionality: 100% brand new and high quality. Specification: Material: high quality carbide tip Tree: 3-flat tree Color: Gold Size: 6mm, 6mm, 8mm, 10mm, 12mm (1/4 ", 1/4 ", 5/16 ", 3/8 ", 1/2 ") Used for: tiles, concrete, brick, glass, plastic and wood, etc. packing list: 5 X Multi-material Drill Bit Used correctly, these drill bits will give you a nice, precise and neat hole for you to fix securely. Professional grade carbide tip is designed to penetrate the toughest material quickly. The double flute effectively eliminates waste. Note: If you are drilling a hard material (glass, porcelain stoneware, marble or granite), please use water for lubrication. Please always add a little water as coolant when drilling, just in case the goods will have the chance to smoke or get dark due to the long period of high temperature operation. In case the pierced fragile goods will be damaged in automobile, please slow down the speed of drilling and piercing pressures. Due to manual measurement, it may be 1-2cm error, and the color of the actual item may appear due to the lighting intensity.