Precision tubing for office chairs, desks and chrome-plated structures
The technical challenge of office furniture
Thousands of cycles, zero noise
Lifting, tilting, swivelling, rolling. Every one of those movements passes through tubing. When the tubing acting as the axle retains a pronounced internal weld bead, play appears: the chair creaks as it tilts, the castor vibrates on hard floors, the mechanism works loose with use. In a quiet office, that noise has an author and a brand name.
The finish is inspected from half a metre away
Office furniture —and high-end and contract furniture even more so— is judged close up and under overhead light. Chrome plating with the porosity of the steel showing through, a drawing mark, a haze: in the catalogue of a design manufacturer, that is not a minor defect, it is a return.
Light without being fragile
Modern furniture calls for slim profiles and slender structures. But a reduced wall thickness with the wrong formability cracks when bent. The challenge is not making the tubing thinner: it is making it thinner without it losing its behaviour.
Applications where you will find us
Task and executive chairs
- Gas spring body and gas lift column The inside of the tubing is the track the piston slides along. Any roughness attacks the seals, slows the movement and ends in a leak: the chair that "no longer goes up". The PRECISE range offers a mirror bore to EN 10305-2, with controlled concentricity.
- Castor axles and pivot points of the tilt mechanism OPTIM range, with an internal weld bead ≤ 0.15 mm and the diameter calibrated to a hundredth of a millimetre: the axle fits with exactly the clearance specified in the drawing, with no play.
- Frame, armrests and exposed base When the tubing is on show, the PREMIUM range provides a bright outer surface ready for direct chrome plating.
Desks with exposed tubing and adjustable structures
- Height-adjustable desks Telescopic columns and lifting mechanisms: a bore free of roughness so that the sliding action is smooth and consistent.
- Legs, cross-rails and tubular structures Thin walls with the formability for tight bends, without cracking or ovalisation.
- Non-circular profiles Square, oval or flat oval section to EN 10305-5, when the desk design requires it.
Chrome-plated structures and mobile furniture
- Direct chrome, zinc and brass plating The PREMIUM range leaves the factory with a bright, non-porous outer surface: the processor saves the polishing stage before the plating bath.
- Silent rolling in mobile furniture Where there is a castor, there is an axle. Where there is an axle, there is OPTIM.
- Screen printing and decorative finishes, when the part needs marking or range differentiation.
The right range for oficina
OPTIMCastor axles, pivots and tilt mechanisms. Internal weld bead ≤ 0.15 mm, simultaneous control of bore and outer diameter
PRECISEGas spring bodies, gas lift columns and adjustable desks. Mirror bore. An alternative to seamless tubing at 40% to 80% lower cost
PREMIUMAll exposed tubing: armrests, bases, legs, chrome-plated structures. Bright outer finish for direct electroplating
Not just the tubing: the finished part
- Coil format or cut-to-lengthCoil supply eliminates end-of-bar scrap on automated lines. Cut-to-length delivers the tubing at exactly the length specified in the drawing, ready to load into the machine.
- Tubing transformed into a component ready to assembleWhen the customer needs it, we do not deliver tubing: we deliver the finished part. Cutting, bending, punching, end forming, threading, machining and surface finishing —to drawing— so that it reaches the assembly line ready to fit. Fewer suppliers to manage, less intermediate handling, fewer errors.
- Documentary certification with every deliveryWe issue certification to 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), depending on what the customer's quality system requires. In-house laboratory at the plant.
Why furniture manufacturers trust Delmàs
A family-owned business in La Roca del Vallès, specialising exclusively in small-diameter welded and calibrated steel tubing (⌀ 3–25 mm).
A chair needs an axle that turns silently, a cylinder with a mirror bore and a structure ready for chrome plating. Delmàs manufactures all three ranges: one technical contact, not three.
Below 8 mm, the supply of precision calibrated tubing all but disappears. That is where we have been working for decades.
Manufacturing powered 100% by renewable energy since 2006, with two photovoltaic self-consumption installations. A figure that contract furniture manufacturers increasingly ask for in their tenders and environmental declarations.
Questions we hear every week
What tubing is used in the gas cylinder of an office chair?
Tubing with a bore free of roughness, so the piston slides without attacking the seals or causing leaks. The PRECISE range (⌀ 8–25 mm) offers a mirror-finish bore to EN 10305-2 and replaces seamless tubing at 40% to 80% lower cost.
Why does an office chair start to creak with use?
Usually because of play in the axles and pivots of the mechanism. If the tubing acting as the axle retains a pronounced internal weld bead, or the diameter is not calibrated, play and friction appear. The OPTIM range keeps the internal weld bead at ≤ 0.15 mm.
Does the tubing arrive ready for chrome plating?
Yes. The PREMIUM range is manufactured with a bright, non-porous outer surface, suitable for direct chrome, zinc or brass plating, with no prior polishing stage.
Do you manufacture sizes that do not exist in the standard catalogue?
Yes, that is our speciality. We do not standardise: if your design needs 6.2 mm or 8.25 mm, that is the size we manufacture, controlled to a hundredth of a millimetre.
Do you deliver the finished component or just the tubing?
Both. As well as tubing in coil or cut to length, we transform the tubing into a finished component ready to assemble: bent, punched, end formed, machined and with whatever surface finish the drawing requires.