Tie-Rod Hydraulic Cylinder Design (ISO 6020)

Yorkshire CAD Services designs bespoke tie-rod hydraulic cylinders to the ISO 6020 range of mounting dimensions, complete with rod buckling and burst pressure calculations for CAT3 and third-party approval. We work with clients across the UK and can design a new cylinder from scratch, adapt an existing one, or produce a fully documented replacement for a unit that is no longer available.

What Is a Tie-Rod Hydraulic Cylinder?

A tie-rod cylinder is built from a smooth barrel closed at each end by a head and a cap, which are clamped tightly against the barrel by several high-tensile threaded rods – the tie-rods – that run the full length of the cylinder and are torqued to a controlled preload. Because the assembly is bolted together rather than welded, it can be dismantled, resealed and rebuilt in service, which is one of the main reasons tie-rod construction remains so widely used in industrial hydraulics.

When to Choose Tie-Rod, Welded or Bolted Construction

The right construction depends on your working pressure, the space available and how the cylinder will be maintained. We design all three types, so our advice is not tied to one method – the table below is a quick guide, and we are happy to talk through the best option for your application.

Construction	Typical standard	Key characteristics	Best suited to
Tie-Rod	ISO 6020 (160 bar series)	Bolted assembly, fully serviceable, standardised interchangeable mountings	General industrial duties where maintenance and standard mountings matter
Welded	CETOP RP 58H	Compact, robust, suited to higher pressures; not designed to be dismantled	Mobile, marine and heavy-duty applications with limited space
Bolted	ISO 6022 (250 bar series)	Heavy-duty, high-pressure, serviceable mill-type construction	High-force, high-pressure and mill-duty applications

Our Tie-Rod Cylinder Design Service

Using SolidWorks Premium™, we produce a full 3D model of your cylinder and every component within it – barrel, head, cap, piston, rod, gland, tie-rods, seals and mountings – together with the manufacturing and general arrangement drawings needed to have it made. We select mounting styles (flange, foot, clevis, trunnion or threaded), rod ends, port sizes and cushioning to suit how the cylinder is installed and loaded, and we draw on many years of hands-on hydraulic design experience to make sure the finished design is practical to manufacture, assemble and maintain.

Design Standards We Work To

We design tie-rod cylinders to the ISO 6020 range of mounting dimensions, which keeps ports, mountings and rod threads interchangeable between suppliers, and we are equally comfortable working to a customer's own specification or reverse-engineering an existing cylinder that needs replacing. We routinely work to BS and ISO standards as well as client specifications, and we make sure each design is fit for purpose and easy to build.

Calculations & Verification

Every cylinder we design can be backed by detailed engineering calculations. We carry out rod buckling and burst pressure calculations as standard, and can prepare full calculation packages for submission to CAT3 checkers or third-party inspectors including ABS, DNV and Lloyd's Register. This makes our designs suitable for regulated and safety-critical projects where the calculations have to stand up to independent scrutiny.

Applications & Sectors

We have designed hydraulic equipment for a broad range of demanding sectors, including military, nuclear, civil engineering, water treatment, Formula One, offshore marine, subsea, chemical and food industries. Wherever your cylinder is destined, we are happy to sign a Non-Disclosure Agreement so that your information stays confidential to you.

What You Receive

Depending on your requirements, a tie-rod cylinder design package can include a fully detailed 3D CAD model, general arrangement and detail manufacturing drawings, and a calculation package – supplied in the file formats your supply chain needs, such as STEP, DWG, PDF and eDrawings.

Frequently Asked Questions

What is a tie-rod hydraulic cylinder?

A tie-rod hydraulic cylinder is built from a smooth barrel closed by two end caps that are clamped together by several high-tensile threaded rods (the tie-rods) running the full length of the cylinder. Because it bolts together rather than being welded, it can be stripped down, resealed and rebuilt, which makes it a popular choice for industrial and repairable applications.

What standard are tie-rod cylinders designed to?

Tie-rod cylinders are usually built to the ISO 6020 range of mounting dimensions, which keeps port positions, mounting styles and rod threads interchangeable between manufacturers. We can design to ISO 6020, to a customer's own specification, or to match an existing cylinder you need to replace.

When should I choose a tie-rod cylinder instead of a welded or bolted design?

Tie-rod cylinders suit general industrial duties where serviceability and standard interchangeable mountings matter. Welded cylinders are more compact and robust for higher pressures and mobile or marine use, and bolted (ISO 6022) cylinders are built for heavy-duty, high-pressure applications. We will advise on the best construction for your duty, pressure and installation.

Can you provide calculations for CAT3 or third-party approval?

Yes. We produce detailed rod buckling and burst pressure calculations on our cylinder designs, and can prepare full calculation packages suitable for CAT3 checkers and third-party inspectors including ABS, DNV and Lloyd's Register.

What do I receive with a tie-rod cylinder design?

Depending on your needs, you receive 3D CAD models, general arrangement and detail manufacturing drawings, and a calculation package, supplied in the file formats your supply chain needs such as STEP, DWG, PDF and eDrawings.

Talk to us about your tie-rod cylinder project. Contact Yorkshire CAD Services for a no-obligation discussion, or call 01642 668 043.