The hydraulic cylinder

The cylinder (or ram) operates much the same as the jack, except that it is more versatile. Since the pump is separate, the cylinder can be used in several positions. By adding
extensions and attachments to the cylinder, you can create a wide variety of hydraulic tools.
The saddle in the plunger serves two important purposes. It protects the plunger
threads from damage and it keeps the end of the plunger from becoming deformed.
Keep the saddle in place at all times. Do not thread attachments into the plunger
and rely on the plunger threads for support. The load must be transferred to the face of the plunger. The threads in the plunger may be stripped if loaded.