Ideal for drilling clean holes to hard materials especially tiles, porcelain ground, granite ceramic glass mirror marble stone masonry brick (not for wood) with Vacuum Brazed Diamond Technology. -Unique Details: Diamond coating enhances the drilling speed; Round Shank compatible with most machines such as Hand Drill, Angle Grinder, Bench Drill; Side flutes help to remove debris and drill holes smooth and fast; Depth mark useful for precise project.