Method for turning root threads through grooving cutter

The invention relates to a method for turning root threads through a grooving cutter. The method comprises the following steps of (1) fixing a workpiece, specifically, clamping the workpiece onto a lathe bed; (2) selecting the cutter, specifically, selecting the grooving cutter with the cutter width less than the width of the thread roots; (3) writing a program, specifically, calculating the Z-axis per-cut offset required for generating a thread angle through the formula: Zi=Xj x tga/2, wherein A represents the Z-axis of a numerical control lathe, i represents the movement amount of the Z-axis, X represents the X-axis of the numerical control lathe, j represents the movement amount of the X-axis, and tga represents the tangent value of the angle alpha; (4) aligning the cutter, specifically, adjusting the relative distance between the cutter and the workpiece; (5) conducting rough machining through a layering method; and (6) conducting finish machining through a left-right interpolationcutter feeding method. A