How to measure hydraulic cylinder

Why Accurate Measurement Matters

• Avoid ordering cylinders that won’t fit your equipment

• Save time and cost on rework or returns

• Ensure optimal performance and safety

• Simplify communication with suppliers (especially for OEM customization)

“How do I measure a hydraulic cylinder correctly for replacement or OEM production?”

Let’s break it down step by step.

Measureing a Hydraulic Cylinder Steps: 

Step1：Check for Nameplate or Part Number Information

Begin by inspecting the cylinder for a nameplate or part number, typically located on the body. This information often provides specifications like bore size, rod diameter, and stroke length, which can simplify the measurement process and ensure accuracy.  Measure the Bore Diameter

Step2：How to Measure Hydraulic Cylinder Bore Diameter 

Measure your cylinder’s bore, which is the internal diameter of the cylinder’s barrel.

• Insert the caliper’s jaws into the cylnder barrel.
• Measure the inner wall to inner wall diameter.
• Keep the caliper level and perpendicular to cyminder axis.
  

Step3：How to Measure Hydraulic Cylinder Rod Diameter

• Place the caliper’s jaws on the smooth rod surface.

• Measure the outer diameter of the rod.

• Avoid measuring over seals or damaged areas.
  

Step4：How to Measure Hydraulic Cylinder Retracted Length

• Fully retract the cylinder rod.

• Measure the distance from center to center of both mounting pin holes.
  
  Important: Do not confuse this with the total body length — always measure mounting point to mounting point.

  

Step5：How to Measure Hydraulic Cylinder Extended Length

• Fully extend the cylinder rod.

• Measure the distance from center to center of both mounting pin holes.

Step6：How to Measure Hydraulic Cylinder Stroke

• Fully extend the cylinder rod.

• Measure the distance the rod extends out of the cylinder barrel.

• Stroke = Extended Length – Retracted Length

Step7：How to Measure Hydraulic Cylinder Mounting Size

1. Note: The width of the earring and the pin hole size directly determines whether you can insert the pin that is already in the unit, be sure to be accurate.

2. Note: The BCD of the flange is the most easy to measure the wrong place, make sure to measure to the center of the screw hole.

3. Note: Many customers only measure the outer diameter of the thread, ignoring the pitch, resulting in threads can not be matched, the pitch must be confirmed!

Common Measurement Mistakes to Avoid

• Not measuring stroke correctly (cylinder must be fully extended)

• Confusing bore size with outer cylinder diameter

• Forgetting to measure installation dimensions

• Reporting body length instead of closed length

• Failing to specify mounting type clearly

How to Share Measurements with AISOAR

After taking your measurements:

✅ Record them clearly in a table
✅ Take photos of the cylinder and mounting details
✅ Email the information to us at oversea@ai-soar.com

AISOAR-Hydraulic-Cylinder-Measurement-Form-2025.pdf

Conclusion

Measuring a hydraulic cylinder correctly is not difficult — but accuracy is key. With the right measurements, we at AISOAR can manufacture or source the perfect cylinder for your equipment.

As a hydraulic cylinder manufacturer with over 26 years of experience, we offer:
✅ High-quality cylinders at competitive prices
✅ Fast OEM customization
✅ Quick delivery worldwide
✅ Expert technical support