Hole saw hole saw drill bit have center pilot holes and side holes for easy scrap removal; diamond bits have gold paint to prevent rust and enhance surface corrosion resistance. The marble hole opener can be used for drilling ceramic tile, marble, glass, granite, concrete and other hard material. Will work with all electric drill and impact drill. The hollow core drill bit are made of high carbon steel with a neat and soomth opening, no broken edges. Small incision resistance, drilling stably and will not breaking the border. When drilling, it is necessary to lubricate the diamond drill bits with water, which can prolong the service life of the drill bit. The ceramic drill bit are made of stable and durable materials, which are durable and can serve you for a long time. The hollow core drill bit is made of high carbon steel with neat and smooth openings, and the center pilot hole and side holes help to remove scrap easily. The hole saw drill bit have gold paint to prevent rust and enhance surface corrosion resistance. It can be used for drilling of hard materials such as tiles, marble, glass, granite, concrete, etc. color: gold Size: Overall length: 83mm/3.27inch Working depth: 58mm/2.28inch Shank length: 25mm/0.98inch Diameter: 35mm/1.38inch Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Including 1*Hollow Core Drill Bit