Internal screw cleaner

The utility model provides an internal screw cleaner which is composed of a power unit, a holder and a cleaning brush. The utility model is used for cleaning inner threads after a nut is welded. The utility model relates to a cleaning method making use of a tool. The power unit is a wind motor; a section of flexible shaft is arranged between the holder and a main shaft of the wind motor; a cleaning brush is a screw tap. Various weld flash in the screw can be effectively removed. The flexible shaft reduces the coaxial requirement; the manual operation is convenient, and the possibility of the blocking of the main shaft is small. Because the overload resistance capability of the wind motor is strong, and the main shaft can not be damaged even if the blocking of the main shaft happens. The utility model has the advantages of easy operation and high cleaning efficiency.