Application · Hydraulic Cylinder
Hydraulic Cylinder Tube Supplier
A cylinder barrel has two dimensional bases, and they are commonly merged into one. The incoming tube is accepted against its product standard; the finished barrel is accepted against the component drawing. This page keeps them apart so the enquiry states which one is actually being asked for.
Two acceptance bases
Incoming tube is not the finished barrel
Confusing the two is the most common cause of a barrel that arrives within its tube tolerance and still cannot be machined to drawing.
| Stage | What governs acceptance | What is measured | What it is not |
|---|---|---|---|
| Incoming tube | The tube as ordered and delivered, against its own product standard and edition. | OD, wall, length, straightness and ovality as delivered. | The finished barrel bore, which does not exist yet at this stage. |
| Finished barrel | The component drawing the cylinder is built to, with its own bore limits. | Bore diameter, roundness, straightness, surface finish and concentricity. | The incoming tube certificate, which says nothing about the machined result. |
Where the barrel bore is machined or honed after delivery, the incoming tube has to provide enough material for that operation. A tube at the low end of its wall tolerance may meet its certificate and still not clean up to the required bore — which is a material-selection question to settle before the order, not a rejection to raise afterwards.
Service inputs
What decides the tube before any tolerance does
Five inputs from the cylinder design narrow the tube before a dimensional discussion is even useful.
Working pressure and bore
Pressure and bore size together set the wall the barrel needs. The tube is selected to meet that requirement, not the other way around — so both have to be stated before a tube is proposed.
Bore finish requirement
Seal type and operating conditions decide the bore surface the cylinder needs. Finish is a component requirement that has to be preserved through honing, not a property of the incoming tube.
Straightness and length
Barrel length and the permitted deviation over that length drive whether the tube can be machined within the drawing. Long barrels are less tolerant of the same straightness figure.
Rod and cap interface
End machining, threading and the interface to the cap and gland make the finished lengths and concentricity requirements component-specific.
Operating environment
Temperature, corrosion exposure and duty cycle change both material selection and whether the tube is supplied in a condition suited to the bore operation.
On the enquiry
State the scope and the basis together
An enquiry that says only 'hydraulic tube' leaves the supplier to guess which acceptance basis applies. These lines remove the guess.
- Whether the enquiry is for incoming tube, finished barrel, or both
- OD, wall, length and the ordered wall convention
- Straightness and ovality requirements with the length they apply over
- Bore diameter and finish required on the finished component, if applicable
- The material and the condition of supply suited to the bore operation
- Machining, honing or end-preparation scope — and who performs it
- Tolerance source with its standard, edition and clause or drawing reference
- Inspection: method, positions, sampling and the agreed conformity decision rule
Enquiry summary
Related
Resolve the neighbouring decisions
These carry the dimensional and tolerance questions that sit underneath this application.
Request a quote
Send the barrel requirement for review
State whether the enquiry covers incoming tube, finished barrel or both, with the dimensional basis and the bore requirement attached to the right one.
Availability, origin, certification and lead time are confirmed on quotation against current company data.