Precision steel tubing with mirror bore for gas springs, shock absorbers and hydraulic cylinders.
Direct alternative to seamless tube. 40–80% lower cost. Same performance.
Gas springs, shock absorbers and hydraulic cylinders share a non-negotiable technical requirement: the inner surface of the cylinder body must be smooth, free of irregularities and dimensionally exact so the piston can slide without friction, leaks or premature wear. Until now, that requirement forced the use of seamless extruded tubing — the most expensive and hardest to source. No longer.
What a gas spring is and why the tube bore is everything.
A gas spring — also called gas strut or gas damper — is a mechanical element that stores energy as compressed gas and releases it in a controlled way to assist the opening or closing of a part. Its basic structure is simple: a cylinder (the tube) with a piston moving inside it, with pressurised gas or oil between them. The performance of the whole assembly depends entirely on the quality of the inner cylinder surface — the tube.
It is the steel tube. It contains the gas or oil and acts as the piston's guide. Its bore must be perfectly smooth so the piston slides without friction and the seal is not damaged.
It moves inside the cylinder in response to the applied force. The piston's rubber seal slides against the inner tube wall on every cycle. If that wall has irregularities, the seal wears out.
It guarantees tightness between the piston and the cylinder wall. It is the component most sensitive to the bore quality: even minimal roughness accelerates its wear exponentially.
With standard tubing — rough bore
- Inner roughness damages the piston seal within the first few cycles
- Gas or oil leakage — the gas spring loses pressure progressively
- The piston brakes and the actuating force drops below the threshold
- Mechanism service life is drastically reduced
- The finished product generates complaints and returns for malfunction
- Real warranty cost far exceeds raw-material savings
With the PRECISE range — mirror bore
- Smooth bright inner surface: the seal slides with zero wear
- Perfect system tightness — zero leaks under normal conditions
- Constant actuating force throughout the mechanism's service life
- Gas spring service life in line with design specifications
- Zero complaints for mechanical failure attributable to the tube
- Raw-material cost savings of 40–80% vs. seamless tube
PRECISE range: the mirror bore your gas spring needs — at welded-tube cost.
The PRECISE range is the most demanding manufactured product in the Delmàs portfolio. Its active inner-calibration process produces a smooth bright inner surface — equivalent to seamless extruded tube — through a high-precision welding technology that controls the process down to the molecular level of the weld. The result is a tube with a bore the piston does not perceive as welded — because, for the function it has to perform, it is not.
PRECISE vs seamless extruded tube — the definitive comparison
The question is not whether PRECISE can replace seamless tube — it already does in gas spring, shock absorber and hydraulic cylinder applications. The question is how much it is costing to keep using seamless when it is no longer necessary.
Present in every environment where a piston moves inside a cylinder.
The PRECISE range is present in every environment where a piston moves inside a steel cylinder — from the gas spring holding your car bonnet open to the front-fork damper of a race bicycle. In all of them, the bore quality determines the service life and performance of the finished product.
Bonnet, boot and sunroof gas springs undergo thousands of opening and closing cycles over the vehicle's life. The piston seal must maintain its integrity throughout — which demands a cylinder bore free of any imperfection.
Gas springs for kitchen furniture, height-adjustable office chairs and bed bases are high-rotation components in the furniture market. Their performance and silence over thousands of cycles determine perceived product quality.
In race bicycles, motorcycles, scooters and kick scooters, dampers are high-performance components working under intense dynamic loads. The cylinder bore must withstand those loads without the seal losing integrity or fluid migrating.
Pneumatic cylinders, hydraulic actuators and industrial gas springs for machinery, automatic shutters and access systems are applications where mechanism reliability over thousands or millions of cycles is critical to process continuity.
From PRECISE tube to finished cylinder: we manufacture the component your assembly line needs.
At Delmàs we manufacture the tube — but we can also manufacture the finished cylinder. As manufacturers with our own transformation capability, we can deliver PRECISE tube already transformed into the exact cylinder body your gas-spring or damper assembly line needs to receive. This means you get the cylinder cut to exact length, with ends machined in the geometry your design specifies — tapered, machined, deformed, reamed, threaded — ready for your operator to fit the piston directly without any prior transformation step. One manufacturer, zero intermediaries, zero operations at your plant.
Exact length
Cut to the exact length specified in the drawing, with tight tolerance. No cutting step at the client's plant.
Machined ends
Inner reaming, threading or any end machining the gas-spring design requires for piston assembly.
End tapering
Cylinder end tapering for piston retention — the most critical operation in gas-spring assembly, carried out at source.
Cylinder ready to assemble
The complete cylinder body — tube + end machining — delivered ready for your line to fit the piston and the seal directly.
This application is present across every sector with piston-and-cylinder mechanisms.
Are you still paying seamless-tube prices for your gas spring? The PRECISE range delivers the same performance at a radically lower cost.
Send us your current specification: diameter, wall thickness and standard. We will send you a PRECISE sample and calculate the real savings vs. your current solution.
- Technical response within 24 h
- Physical sample
- Comparative study vs seamless tube