Determine the thrust and tension on the piston rod based on the required force for the job. When selecting a cylinder based on this, there should be a slight margin for the output force of the cylinder. If the cylinder diameter is selected too small, the output force is not enough, and the cylinder cannot work normally; However, a large cylinder diameter not only makes the equipment bulky and costly, but also increases gas consumption, resulting in energy waste. When designing fixtures, force increasing mechanisms should be used as much as possible to reduce the size of the cylinder. Below is the formula for calculating the theoretical output of a cylinder: F: cylinder theoretical output force (kgf) F ': output force at an efficiency of 85% (kgf) - (F'=F × 85%) D: cylinder diameter (mm) P: working pressure (kgf/cm2) Example: What is the theoretical output force of a cylinder with a diameter of 340mm and a working pressure of 3kgf/cm2? What is the output of sprouts? Connect P and D, find the points on F and F ', and obtain: F=2800kgf; F '=2300kgf When selecting the cylinder diameter in engineering design, it can be found from experience table 1-1 based on its operating pressure and theoretical thrust or tension. Example: There is a cylinder with a working pressure of 5kgf/cm2, and its thrust is 132kgf when the cylinder is pushed out