Slender shaft processing, installation on the machine: one end with a chuck clip, the other end with * support, both ends with * support. If the same radial force under the force, the above two kinds of installation methods compared to the latter form of bending deformation is small, so the elongated shaft of the turning, the machine should take the first installation. With the knife holder, the central frame is the current industrial enterprises often use a processing of the shaft of the auxiliary. The correct use of auxiliary tools to ensure the smooth progress of cutting and improve the quality of the workpiece processing plays an important role. After the reduction of the diameter of the workpiece in the necking part, the flexibility increases, the necking has the self-position effect, can eliminate the deformation due to the blank itself in the chuck forced clamping under the axis line with the skew effect, improve the machining accuracy The