I am building a ground pushing and pulling probe similar to the pic attached. A probe rod is hydraulically clamped and held in place using a split clamp jaws that have a pyramid grip pattern made from hardened tool steel 58HRC similar to the pics. That particular machine (in the picture) can hold up to 200kN of push/pull force. My question is how do I calculate the size and force of the hydraulic cylinder to hold a similar load 200kN? The clamp jaws will be approx. 150mm high and match the dia. of the probe pipe which is 36mm with a hardness of approximately 30-40HRC. The clamp won't quite go the full diameter and will have a little gap at the ends. The pyramid serrations will be as per the pic 1.2 x45deg. Thanks for looking and any suggestions are much appreciated and welcome. Thanks Kindly. Merry Christmas to all.