How to Measure a Hydraulic Cylinder for Replacement

When replacing a hydraulic cylinder, getting accurate measurements is essential. An incorrectly sized replacement can cause costly downtime, fitting issues, or even equipment damage.

This guide covers the key cylinder measurements you’ll need, the tools to use, and practical tips to ensure your replacement cylinder fits and performs correctly.

Step 1: Identify the Cylinder Type

Before measuring, determine which type of hydraulic cylinder you’re replacing:

• Single acting – hydraulic force extends the rod, gravity/spring returns it.
• Double acting – hydraulic force extends and retracts the rod.
• Displacement (ram) – uses hydraulic fluid to push directly on the piston surface.

Not sure which type you have? Read our guide: A Guide to Hydraulic Cylinders

Step 2: Gather the Right Tools and Safety Equipment

Working with hydraulic equipment always use the right tools;

• Tape measure
• Digital calipers or micrometer (for bore and rod diameter)
• Thread gauge or known fitting size (for ports and rod end threads)
• Thread identification kit (modern alternative)

Step 3: Measure the Key Cylinder Dimensions

Bore (Piston Diameter)

The bore is the inside diameter of the cylinder barrel.

• If disassembled: measure the piston or inside tubing diameter.
• If assembled: measure the outside barrel diameter and subtract the tubing wall thickness.

Example: An outer barrel of 2″ with 0.25″ walls gives a 1.5″ bore.

Rod Diameter

The rod transfers force during operation, so correct sizing prevents bending.

• Made from chrome-plated or stainless steel.
• Use calipers/micrometres to measure thickness (rod diameter).

Stroke Length

The stroke is the distance the rod travels:

• Formula: Stroke = Extended length – Retracted length
• If installed, follow lock-out/tag-out procedures before measuring.
• Sometimes hydraulic pressure may need to be applied to fully extend the rod.

Retracted & Extended Lengths

• Retracted length: From a fixed cylinder point to the rod end when fully retracted.
• Extended length: Same measurement with the rod fully extended.

Step 4: Check the Rod End Style

Rod ends vary by equipment type. The most common include:

• Standard Male
• Standard Female
• Intermediate Male

Use a thread gauge or thread ID kit to confirm type and size.

Step 5: Determine Mounting Style

Cylinder mounting styles differ depending on application:

• Flange mount – common in industrial systems
• Pivot mount – often used in mobile machinery

Step 6: Identify Hose Port Size and Location

Each cylinder has hydraulic hose ports, usually female-threaded, that connect to male hose crimps.

Check for:

• Thread type and pitch (using gauges or ID kits)
• Port size
• Location and orientation

If ports differ from your hoses, adapters can usually be fitted.

Step 7: Consider the Operating Environment

The right cylinder also depends on where it will be used. Consider:

• Temperature range
• Exposure to dust, dirt, or corrosives
• Seal and wiper technology (modern polyurethane and composite seals last longer in harsh conditions)
• Rod coatings for corrosion protection

Step 8: Confirm Working Pressure

Match the cylinder rating to your hydraulic system:

• Medium duty: up to 1,500 PSI (≈100 bar)
• Heavy duty: up to 3,000 PSI (≈200 bar)
• Very high pressure: up to 10,000 PSI (≈700 bar) for jacks, presses, and excavators

Check manufacturer manuals or measure at the cylinder ports.

Step 9: Compare Against Manufacturer Drawings

Finally, compare your measurements with the manufacturer’s technical drawings or use their online configuration tools. Many suppliers now provide 2D and 3D models to check compatibility before ordering.

Final Thoughts

Accurate measurement ensures a correct cylinder replacement, avoiding costly errors and downtime.

Need support? Our hydraulic specialists can help measure, source, and configure the right cylinder for your system. Contact us today for expert advice.