Our factory often uses all kinds of precision tops (Fig. 1). During the manufacturing and maintenance process, the tail is usually processed first, and then the 60° cone is machined by the tail on the universal cylindrical grinding machine. Due to the runout error of the machine head spindle (0.005mm) and the error caused by the installation alignment, the 60° cone of the workpiece after the processing has a beating amount of the tail, which is ideally only 0.005mm, which cannot meet the drawing requirements. for