Special cutter for sealing hole

The utility model provides a special cutter for sealing holes, which is arranged to be extending along the axial direction. The special cutter is successively provided with a handle and a blade part in the axial direction. The blade part comprises a sinking-hole blade arranged axially close to the handle end. The sinking-hole blade is provided with a lateral part positioned on the outer side of the special cutting tool, and an end part with its back facing the handle. The end part is provided with an O-type ring blade and the O-type ring blade is a cutter groove recessed into the end part. The blade part also comprises a bottom-hole blade positioned axially far from the tail end of the handle. The bottom-hole blade is provided with a lateral part positioned on the outer side of the special cutting tool, and an end part with its back facing the handle. The radial width of the bottom-hole blade is smaller than the radial width of the sinking-hole blade. By utilizing the single special cutter, a sealing hole of