Hi! This is my first post on here. I need to purchase an air cylinder, most likely hydraulic. The cylinder will have a forming die attached on the end and will be used to crimp two small stainless steel tubes together. The crimp will occur at an offset of .004 inches from each end of the tubes. They are thin tubes, as the ratio of the inner diameter and the thickness are less than 20. How can I calculate the pressure required to execute this task? Is there a specific set of formulas? Any help is greatly appreciated.