[Espeefan]

Two things determine the max force of a hydraulic cylinder. The area of the piston, and the pressure of the oil pushing it.

A note of interest that some might not think all that much about. The rod end side of a cylinder's piston has less surface area, as opposed to the opposite end, so cylinders have less lifting or pulling capacity, from that direction. They also cycle faster when you fill them from the rod end side because there is less volume to fill with oil.