Thread hard turning tool

The invention relates to a thread hard turning tool. The tool comprises a blade, a cutter handle, a spring gasket and a fastening bolt; the cutter handle is connected with a lathe cutter mounting frame, and the blade is fixed with the cutter handle through the fastening bolt; the spring gasket is arranged on the fastening bolt to prevent the threaded connection from loosening in a sleeving mode; and when internal threads are machined, the cutter handle is of a linear structure, and when external threads are machined, the cutter handle is of an L-shaped structure. The V-shaped guiding and positioning principle is ingeniously utilized, installation guiding and deflection fixing of the blade are achieved, and accurate positioning and repeated clamping accuracy of the blade can be guaranteed. According to a detachable hard turning tool structure, a blade installation connector is universal, the cutter handle is replaced, a blade of a new structure does not need to be adopted, the detachable hard turning tool stru