The main cutting part of a cylindrical countersink is the end cutting edge, while the bevel angle of the spiral flute is considered the rake angle. The tip of this drill has a guide post that fits tightly into the existing hole in the workpiece to ensure good centering and guidance. The tool handle is designed to be cylindrical, which is convenient for clamping. The cutter head part is tapered and has an oblique hole running through it. The beveled edge of the tapered tip has a cutting edge that can be used for cutting. The through hole serves as a chip discharge hole, and the iron chips will be rotated and discharged upward. The centrifugal force will help scrape the iron chips from the surface of the workpiece to avoid scratching the surface of the workpiece and affecting the quality. This kind of guide post is detachable, and the guide post and countersink can also be made into one piece.In general, a countersink drill is a tool specially used for processing smooth holes and countersinks. Its structure and design help improve work efficiency and processing quality.