Material Structure: They are generally made of high-strength alloy steel or heat-treated tool steel. This ensures that the parts do not deform under high pressure and friction. Precision Grinding: The outer surfaces of the parts are smoothed to very low tolerances (at the micron level). This polished surface minimizes friction with other parts. Various Sizes: A set of parts produced in different diameters and lengths is seen in the image; this indicates that the parts are customized according to specific machine models or different power capacities. Assembly Details: The small holes or threaded sockets seen at the top are for connecting these parts to the main mechanism or an actuator.