A two-piece clamping element comprises two separate, i.e., non-integral, opposing first and second clamping jaws forming a laterally open cavity to receive a pin or rod-shaped element. Each clamping jaw has a bore aligned with one another to receive a screw, wherein a pivot bearing is arranged opposite said cavity allowing the two opposing clamping jaws to come in contact to one another. The pivot bearing comprises at least one set of complementary part-cylindrical bearing surface portions. An anti-rotation pin extends between the two jaw members.