Tie-Rod vs Welded Hydraulic Cylinders: Which to Specify

How each construction works

A welded cylinder has a single-piece welded body with machined end caps and tie rods passing through the cap only, so the full bore is available for load. A tie-rod cylinder has rods running the full length of the body, bolted to both caps, which gives a compact, repairable unit in standard mounting dimensions.

Strength and weight

For a given bore and pressure the welded body carries higher buckling resistance because the tube is continuous, so a welded cylinder usually reaches a larger bore in the same envelope. The tie-rod cylinder is heavier for the same bore because of the extra steel in the rods.

Repairability in the field

A tie-rod cylinder can be stripped and re-bored on site, and the seals can be replaced without removing the cylinder from the machine. Welded cylinders are lighter and cheaper but need the seals replaced with the cylinder removed in most cases.

Typical applications

Tie-rod cylinders are standard on sanitation, mining, agricultural and offshore equipment where parts interchangeability matters. Welded cylinders are used where weight and maximum bore in a given length matter, such as injection moulding machines, dump trucks and long-stroke applications.

How to order

Specify the mounting standard (NEMA, ISO or SAE), the bore and stroke, the working pressure, the rod end and cap mounting, and the fluid. We will confirm whether a tie-rod or welded construction is the better fit for the duty.