American Style Modern Lamp,Nordic Modern Design Lamp,Living Room Decoration Lamp,Modern Pendant Light Fixtures ZHONGSHAN DIKA LIGHTING CO.,LTD , http://www.dikalighting.com 1. Overview The bolt hole position refers to the position of the two bolt counterbore at the top of the large end of the connecting rod relative to the center line and the bottom surface of the workpiece. The detection of this parameter is essentially to confirm the position of the two bolts symmetrically connected to the connecting rod assembly. Accuracy. In Figure 1, L_1 and L_2 are the distances from the two counterbore to the centerline of the connecting rod, and d_1 and d_2 are the distance from the two counterbore to the bottom surface of the workpiece.