What are tie-rod cylinders?

A tie-rod hydraulic cylinder uses threaded steel rods to hold two end caps to the ends of the cylinder barrel. Applications can use anywhere from 4 to 20 tie-rods depending on the bore diameter and operating pressure. A strong advantage of the tie-rod design is that it can be easily disassembled and examined for repair. Tie-rod cylinders are utilized in a large majority of industrial and heavy-duty manufacturing applications.

What are welded rod cylinders?

In a welded rod hydraulic cylinder, the barrel is welded directly to the end caps. The head cap can use a variety of retention methods such as threading or bolting. This design is generally well-received for mobile equipment due to the compact construction, internal bearing lengths, and duty cycle compared to tie-rod construction. However, the design does make inspection and repairs more difficult in the field due to requiring less conventional tools and equipment.

What are telescopic cylinders?

Telescopic hydraulic cylinders are typically used when a stroke length is required which is considerably longer than the retracted length. They are designed with a series of steel tubes, called stages, each progressively smaller in diameter and nested within each other.

Types of Hydraulic Cylinders

No two hydraulic cylinder applications are the same. Because of this, there isn’t a simple “one size fits all” cylinder that works for every project. And identifying the right types of hydraulic cylinders for your applications can be difficult. However, using the correct cylinder style is essential to protect your equipment and ensure optimal performance.

The first step to selecting a cylinder is understanding the different available types of hydraulic cylinders.

Different Types of Hydraulic Cylinders

The three most common types of hydraulic cylinders are NFPA tie-rod cylinders, welded rod cylinders, and telescopic cylinders. Each model has a distinct construction and is built to handle different operations. Additionally, there are various classifications of welded rod and telescopic cylinders, including single-acting and double-acting designs, which offer their own unique advantages.

Read below to learn about the different cylinder styles and their applications. Contact Hydraulic Cylinders, Inc. with any questions or for help determining the right hydraulic cylinder for your operations.

Common Applications of Hydraulic Cylinders

NFPA Tie-Rod Cylinders

NFPA Tie-rod hydraulic cylinders, designated by the National Fluid Power Association (NFPA), are standardized hydraulic cylinders that adhere to strict guidelines set forth by the association. These standards ensure interchangeability, reliability, and safety, which are critical for users across various industries. They feature a cylinder barrel, piston, piston rod, and tie rods to hold the cylinder head and end caps together. This design allows these units to be easily disassembled and reassembled for quick maintenance and examinations.

NFPA tie-rod cylinders are commonly used to power the following applications:

Manufacturing equipment, including assembly lines, conveyor systems, and automation machinery
Material handling equipment, such as conveyor systems and lift trucks
Primary metals, such as steel mills and foundries
Clamping, shearing, and forging, as well as for pressing operations
Plastics and Molding used in injection molding, molding equipment, and other plastics-related machinery

Depending on bore diameter and operating pressure, tie-rod cylinders may contain anywhere from four to twenty tie rods.

Welded Rod Cylinders

Welded rod hydraulic cylinders are known for their robust, compact design and high durability, making them ideal for demanding industrial and mobile applications. Unlike tie-rod cylinders, the end caps of welded cylinders are permanently joined to the barrel through welding, which eliminates external tie rods and reduces potential leak points. This design allows for a smaller overall footprint and greater structural integrity, especially under high-pressure conditions. Welded cylinders offer various mounting options, such as clevis, trunnion, or flange mounts, which are typically welded directly onto the body, enhancing versatility in installation. Although they are generally harder to repair than tie-rod cylinders, their sealed design, customizability, and ability to operate reliably in harsh environments make them a preferred choice in construction, agricultural, and heavy machinery applications. This allows welded rod cylinders to be used for heavier-duty, high-pressure applications, including:

Construction equipment, including excavators, bulldozers, and cranes
Agricultural equipment, including tractors and loaders
Material handling machines, forklifts, reach stacker container handler, and conveyors

The double-acting design offers greater efficiency, precision, and speed, making welded rod cylinders highly durable for various industrial applications. They have a long service life and ensure reliable long-term operations.

Telescopic Cylinders

Telescopic cylinders, also known as multistage cylinders, are designed with a series of steel tubes (stages) that provide extended stroke lengths in a compact package. Available as single-acting telescopic cylinders (SAT) or double-acting telescopic cylinders (DAT), these models are excellent for use with mobile, heavy-duty equipment.

SAT cylinders use hydraulics to extend their piston in one direction, relying on gravity for retraction. These units have a simple build that reduces the risk of failure and minimizes maintenance costs. They are excellent for applications with constant dumping, raising, or tipping functions, including:

Dump trucks and trailers
Refuse collection vehicles, for compacting or unloading waste
Agricultural equipment, such as grain trucks or silage wagons for tipping operations
Lifting platforms and hoists, where space is limited but significant extension is required
Mobile cranes and aerial work platforms, for height extension using minimal storage space

Like double-acting welded rod cylinders, DAT cylinders use hydraulic pressure to both extend and retract the rod or sleeve. While they have a more complex construction than their single-acting counterparts, they offer increased precision, control, and flexibility. DAT cylinders are used for many heavy-duty applications, including:

Construction equipment, including dump trucks, trailers, and hoists
Mobile cranes, telescopic booms
Industrial equipment, including forklifts, robotic arms, and conveyor belts
Recycling and waste handling, including front loader, rear loader, side loader, and rolloffs
Oil and gas machines, including drill rig equipment

While similar, SAT and DAT cylinders offer different advantages for industrial projects. Learn more about the Differences Between Single-Acting and Double-Acting Hydraulic Cylinders to choose the right type of cylinder for your operations.

Find the Right Type of Hydraulic Cylinder for Your Application at Hydraulic Cylinders, Inc.

Hydraulic Cylinders, Inc. is your full-line supplier of hydraulic cylinders and cylinder component parts. Our team of experts will help you choose the right type of hydraulic cylinder for your application and equipment, no matter the project. From offering same-day shipping on all in-stock inventory to tailoring custom cylinder designs to fit non-standard machinery, we are ready to supply suitable solutions to keep your job site moving.