What causes of the lathe can affect the out of tolerance of the cylindricity of the machined workpiece?

(1) The parallelism between the spindle axis and the bed saddle guide rail is out of tolerance.

(2) The guide rail of the bed is seriously worn.

(3) When clamping the workpiece with two sharp points, the axis of the tailstock sleeve does not coincide with the axis of the main shaft.

(4) The fixing screw is loose, resulting in the horizontal change of the lathe.