To provide a right-left screw capable of securing stable quality as a standardized product, and to provide a rolling dies for the same by realizing a function of the right-left screw as a perfect means for preventing looseness.

The right-left screw is formed with a right-hand thread and a left-hand thread on the same surface. Cross sectional shape of the threads of the right-hand and the left-hand screws have an outline of a part formed by overlapping shape of the right-hand thread with shape of the left-hand thread. The rolling dies 1 for manufacturing these right-hand and left-hand screws is formed with a blade 11a for forming the right-hand thread and a blade 11b for forming the left-hand thread on the same machining surface of the rolling dies. Cross sectional shape of the rolling dies has an outline formed by projecting a shape, which is formed by overlapping separate shapes of the blade for forming the right-hand thread and the blade for forming the left-hand thread, in the vertical direction of the cross section.