Efficient & Smooth Drilling: This diamond core drill comprises premium aluminum alloy components, and high-quality diamond grits ensure longer coring life. Diameter: 8″ / 203 mm, Useful length: 14″ / 355 mm. Engineered For Exact Fitting: With 5/8-11 Universal Thread, this core drill bit allows easy and fast assembling to a standard fixed core or hand-held drilling machine. It is also suitable for various devices. Humanized Structure: Our diamond wet coring bit features chip removal holes, highly regular saw teeth, and concentric axes design. The innovative design allows it high drilling performance while keeping a long lifetime. Simple Operation: The core drill can be used for wet drilling to content your work needs. Start drilling at the vertical position and continue to dig deep. A bit of water can prolong the service life. Versatile Uses: Our concrete core drill is designed for drilling concrete, red brick, marble, and other materials on conditions, such as installing air conditioners, pipes, stair railings, highways, and airports, etc.