This diamond countersink drill bits is designed for Bevelling，Enlarging, Grinding and Polishing the exsit holes or shaping edge of materials.
HIGH-GRADE DIAMOND: High quality dimoand grain make the edge of the hole smooth and clean, and can achieve excellent surface effect.
The chamfer effectively eliminate the rough holes of ceramics, tiles porcelain marble and other materials. ATTENTION: This i
1pc Adapter for Core Bits Conversion 5/8-Inch-11 to 3/8-Inch Hex Shank
This is not a core bit for drilling. It doesn’t make holes but it bevels the hole cleaning and reinforcing the borders when the borders are chipped or need to be clean； Reduce the contact surface, tilt moderately, do not press directly with force, shake slowly and slightly along the force, and the range should not be too large.
