Shandong Xinsuju Steel Co.,Ltd. , https://www.sawlpipe.com Spherical workpieces are often encountered in machining and maintenance (Fig. 1). The measurement method of the radius of curvature is now described as follows. As shown in Fig. 2, the radius of the curvature circle of the table cover workpiece ABCD is: OB=OC=R, the thickness of the table ABCD is: EF=h, OF=x, and the diameter of the end face circle of the table workpiece is: AB=L_1 , CD = L_ (20).