The clamping surface of each clamp is bored and reamed to the exact size of the polished rod. Additionally, both ends are machine-squared with the hole to prevent eccentric loading if the hanger bar is flat. The clamp exerts a 2:1 mechanical advantage in the ratio of distance from the center of the rod to the center of the bolt and from the rod to the center of the pin. Contact areas are spaced to give maximum clamping effect. We can also provide products customized according to customers' requirements