When processing the roll of the rolling head, since the roll is more eccentric and the eccentricity is small, in the past, the method of repeatedly changing the sleeve as shown in FIG. 1 and re-aligning the eccentricity of the rotation is used. This is not only troublesome but also inefficient and of poor quality. Now we have designed a set of adjustable eccentric clamps as shown in Figure 2. The end projections of the clamps match the three-jaw chucks and the three-jaw chucks are installed.