Precision tubing for cars and passenger vehicles: fluids, mechanisms and structure
The technical challenge the automobile
Zero tolerance on the line
The OEM and the Tier 1 assemble on an automated line, at a rate of seconds per part. A variation in diameter between batches generates rejects and stops the line. The tubing has to hold its tolerance batch after batch, from the first to the last part of the contract.
Homologation and traceability as a contractual requirement
In automotive, product certification, material traceability and conformity with EN 10305, ASTM 513 and SAE are not an optional document: they are a condition of delivery. Every supply comes with its certification.
The cost of seamless tubing
Cooling circuits and gas springs have historically used extruded seamless tubing, out of fear that the weld will leak. That fear has a price: seamless is 40% to 80% more expensive, with uncertain and unpredictable lead times.
The scrap from the bar
Supply as tubing cut to standard lengths leaves end-of-bar scrap that, at automotive volumes, represents 10% to 15% of the material.
Applications where you will find us
Cooling and oil (fluid management)
- Alternative to seamless tubing The PRECISE range offers a mirror-finish bore to EN 10305-2 that meets the sealing requirements of a low-pressure circuit, at 40% to 80% lower cost than seamless and with availability in weeks, not in uncertain lead times.
- Clean bore for flow No roughness or beads to disturb the passage of the fluid or trap particles.
- Certification with every delivery EN 10204-2.2 or 3.1 depending on what the OEM's quality system requires.
Sun visor and sunroof
- Cable routing The tubing routes the electrical cable to its destination with a controlled bore and an internal weld bead ≤ 0.15 mm (OPTIM range), so the cable passes and slides without snagging.
- Sliding of the mechanism When the sunroof mechanism slides over the tubing, the surface —bore or outer, depending on the design— has to be smooth and consistent.
Boot blind shaft
- Rotation with no noise or play OPTIM range, with simultaneous control of outer diameter, bore and wall thickness and an internal weld bead ≤ 0.15 mm: the shaft turns smoothly, without tipping and without the noise the user would notice in the cabin.
- Batch-to-batch consistency The diameter calibrated to a hundredth of a millimetre ensures the mechanism assembles the same across the whole run.
Seat guides
- Simultaneous control of bore and outer diameter The headrest guide is a textbook case: two elements sliding one inside the other with a precise, play-free travel. The OPTIM range controls both diameters at once.
- Outer finish and fit When the guide is on show or demands smooth sliding over the outer surface, the PREMIUM range provides the finish.
- Scope note the tubular structure of the seat (the frame that passes crash tests) is usually structural tubing of a diameter and mechanical properties outside Delmàs's focus. This page centres on guides and mechanisms of the seat, not on the safety structure.
Cable terminals
- Small calibrated diameter The tubular terminal requires an exact bore to house and secure the cable. It is the small-diameter territory where Delmàs has no competition.
- Cut-to-length Delivered at exactly the length specified in the drawing, ready for the crimping or fixing operation.
The right range for Cars and passenger vehicles
PRECISECooling, oil, gas springs and fluid conduction. Mirror bore. An alternative to seamless at 40% to 80% lower cost
OPTIMSeat guides, blind shaft, sun visor/sunroof mechanism, terminals. Simultaneous control of bore and outer diameter, weld bead ≤ 0.15 mm
PREMIUMExposed parts and components with an outer fit and finish. Bright outer surface
Supply and service
- Coil supplythe line does not stop and there is no end-of-bar scrap. Continuous coil feed eliminates stoppages for bar changes and end-of-bar scrap, which at automotive volumes amount to 10% to 15% of the material. It is the standard format for automated lines.
- Homologation and traceability with every deliveryCertificate EN 10204-2.2 (declaration of conformity with non-specific inspection results) or EN 10204-3.1 (inspection certificate with specific results for the batch supplied), conformity with EN 10305 / ASTM 513 / SAE, depending on what the OEM's quality system requires. In-house laboratory at the plant.
- Tubing transformed into a component ready to assembleWhen the customer needs it, we deliver the finished part —cut, bent, punched, end formed, machined— ready for the assembly line.
Why OEMs and Tier 1s trust Delmàs
A family-owned business in La Roca del Vallès, specialising exclusively in small-diameter welded and calibrated steel tubing (⌀ 3–25 mm).
The PRECISE range technically replaces seamless tubing in fluids and gas springs, at a fraction of the cost and with predictable availability.
Coil supply reduces the total process cost by 10% to 15% compared with tubing in bar form.
Manufacturing powered 100% by renewable energy since 2006, with two photovoltaic self-consumption installations. More and more OEMs require this for their own carbon footprint reporting.
Questions we hear every week
Can you replace seamless tubing in a cooling circuit?
Yes. The PRECISE range offers a mirror-finish bore to EN 10305-2 that meets the sealing requirements of a low-pressure circuit, at 40% to 80% lower cost than seamless and with predictable lead times.
Do you supply in coil for an automated line?
Yes. Coil supply is the standard format for automotive: continuous feed with no stoppages for bar changes and no end-of-bar scrap, reducing the total process cost by 10% to 15%.
Do you provide product certification and traceability?
Yes, with every delivery. We issue an EN 10204-2.2 or 3.1 certificate, with conformity to EN 10305, ASTM 513 and SAE, depending on what the customer's quality system requires.
What tubing is used in a headrest guide?
Tubing with simultaneous control of bore and outer diameter, so the travel is precise and play-free. The OPTIM range controls both diameters at once, with an internal weld bead ≤ 0.15 mm.
Do you manufacture non-standard sizes?
Yes, that is our speciality. If your design needs 6.2 mm or 8.25 mm, we manufacture that size, controlled to a hundredth of a millimetre.
More subsectors in Automotive
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