Novel thread cutter bar

The utility model relates to a novel thread cutter bar, comprising a cutter bar body and a tool bit, wherein a cutter tooth of the tool bit is in a multi-tooth rotary form; a rotating shaft is arranged at the center point of the cutter tooth; the cutter bar body comprises an outer sleeve and an inner sleeve; the inner sleeve can stretch relative to the outer sleeve; the external sleeve is in a hollow cylindrical structure; a through hole is formed in the pipe wall of the outer sleeve along the axis direction; and a row of buckle elements are arranged on the inner side wall of the pipe wall of the external sleeve. After the technical scheme is adopted, axial work-pieces with relatively deep inner holes can be processed by adopting a telescopic mechanism; axial work-pieces with relatively hollow inner holes can also be processed; when the tool bit on the internal sleeve reaches a to-be-processed position, the buckle elements on the external sleeve can be buckled in a groove in the internal sleeve; and the internal sleeve is buckled, so that the tool bit does not move when processed; the processing accuracy of the work-pieces can be ensured; and a lubricating liquid dropping device is arranged on the tool bit, so that the cooling effect on the tool bit can be reached; and meanwhile, the novel thread cutter bar can play a lubricating role.