While the basic principle is consistent, hydraulic cylinders are manufactured in several distinct designs to suit various applications. A primary classification is between tie-rod cylinders and welded body cylinders. A tie-rod hydraulic cylinder uses high-strength threaded rods to hold the end caps to the barrel. This design is common in industrial applications and allows for easier maintenance and disassembly. In contrast, a welded body hydraulic cylinder has the end caps directly welded to the barrel, creating a more compact and robust unit often used in mobile equipment where space is a consideration.

Another important distinction is between single-acting and double-acting hydraulic cylinders. A single-acting hydraulic cylinder admits pressurized fluid to only one side of the piston to extend the rod. The return stroke is typically accomplished by a spring or by the force of gravity acting on the load. A double-acting hydraulic cylinder, which is more common, uses hydraulic power for both extension and retraction. By directing fluid to either the cap end or rod end port, the double-acting hydraulic cylinder provides positive control over movement in both directions, making it highly versatile.

The physical configuration of the cylinder also varies. A telescopic hydraulic cylinder, also known as a multi-stage cylinder, features a series of nested tubular sections. This design allows for a very long stroke from a compact retracted length, which is useful in applications like dump trucks and garbage compactors. The design of a hydraulic cylinder can also be differentiated by its mounting style. Common mounts include clevis, flange, and trunnion mounts, which determine how the hydraulic cylinder is attached to the machine frame and the load, influencing how forces are transferred.

Selecting the appropriate hydraulic cylinder type depends on the specific requirements of the application. Factors such as the required force, stroke length, available space, and operating environment all influence the choice. A tie-rod cylinder might be selected for a factory machine for its serviceability, while a rugged welded body hydraulic cylinder is better suited for the harsh conditions of a construction site. Understanding these different designs allows engineers and technicians to specify the correct hydraulic cylinder for reliable and efficient system performance.