Precision tubing for guides, rails, shafts and structural components
The technical challenge of mechanical engineering
The exact dimension or the compromise
A mechanical design defines diameters, clearances and fits for a functional reason. When standard tubing only exists in nominal sizes, the engineer has to choose: redesign around the available material, or accept a fit that is not optimal. Manufacturing the exact size eliminates that compromise.
Bore and outer diameter matter at once
In a guide, a shaft, a support, the outer diameter often determines one fit and the bore determines another —the passage of a shaft, the seating of a bearing, the sliding of a component. Tubing that controls only one of the two faces forces a subsequent machining operation. Controlling both at once saves that operation.
Repeatability is what industrialises
A perfect part is no use if the next one is different. In a mechanical run, constant batch-to-batch tolerance is what allows assembly without manual adjustment and automation of the line.
The internal bead no one sees, but that gets in the way
In welded tubing, the internal weld bead invades the bore: it obstructs the passage of a shaft, the sliding of a piston or the seating of a component. Controlling it is what makes welded tubing behave like seamless, at a fraction of the cost.
Applications where you will find us
Precision guides and rails
- Sliding fit to a hundredth The OPTIM range controls outer diameter, bore and wall thickness simultaneously, with an internal weld bead ≤ 0.15 mm: the fit between guide and sliding element is exactly what the drawing specifies, with no play or seizing.
- Smooth bore When the sliding must be fine and repeatable, the PRECISE range provides the mirror bore to EN 10305-2.
- Non-circular profiles Square, oval or flat oval section to EN 10305-5, when the guide has to prevent the sliding element from rotating or fit into a non-round housing.
Structural components
- Exact wall thickness, not oversized Exactly the wall thickness the structural calculation calls for, with the formability to bend without cracking or ovalisation. No more wall than needed (weight and cost) and no less (failure).
- Surface ready for finishing When the component is on show, the PREMIUM range provides the bright outer surface for electroplating or direct painting.
- Batch-to-batch consistency, so that every structure fits the same at assembly.
- Scope note (see section 11) Delmàs manufactures in the ⌀ 3–25 mm range. Heavy, large-diameter, highly stressed structure is outside our focus. This application centres on small-diameter structural components.
Shafts and supports
- Shaft calibrated to a hundredth The outer diameter controlled for the fit with bushings and bearings; the bore controlled when the shaft is hollow or houses another element. Internal weld bead ≤ 0.15 mm so nothing obstructs the bore.
- Controlled concentricity So the shaft turns without eccentricity or vibration.
- From tubing to finished part When the customer needs it, we deliver the shaft or support already cut, bent, punched, machined and threaded, ready to assemble.
The right range for Mechanical
OPTIMGuides, shafts and supports where bore and outer diameter matter at once. Simultaneous control, weld bead ≤ 0.15 mm
PRECISEGuides with fine sliding, hollow shafts and elements that demand a finished bore. Mirror bore. An alternative to seamless at 40% to 80% lower cost
PREMIUMExposed structural components and parts with a finish. Bright outer surface for direct electroplating
Supply and service
- Simultaneous control of bore and outer diameterIt is the capability that saves subsequent machining operations: the tubing arrives with both faces already in tolerance.
- 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— ready to assemble. One manufacturer instead of several suppliers.
- Coil format or cut-to-lengthto eliminate end-of-bar scrap on automated lines.
Why engineering trusts Delmàs
A family-owned business in La Roca del Vallès, specialising exclusively in small-diameter welded and calibrated steel tubing (⌀ 3–25 mm).
The simultaneous control of both diameters is what sets Delmàs apart and what saves the engineer a machining operation.
We manufacture the dimension the design calls for, to a hundredth of a millimetre, without being tied to a catalogue.
Manufacturing powered 100% by renewable energy since 2006, with two photovoltaic self-consumption installations at the plant.
Questions we hear every week
Do you manufacture the exact size my design calls for, even if it is not in the catalogue?
Yes, that is our speciality. We do not standardise: we start from your drawing and manufacture the exact outer diameter, bore and wall thickness, to a hundredth of a millimetre. If your design calls for 8.25 mm, we manufacture 8.25 mm.
Do you control the bore and the outer diameter at the same time?
Yes. The OPTIM range controls both diameters and the wall thickness simultaneously, with an internal weld bead ≤ 0.15 mm. It is what avoids a subsequent machining operation when both faces of the tubing matter.
Can welded tubing replace seamless in a guide or a hollow shaft?
Yes. The PRECISE range offers a mirror-finish bore to EN 10305-2 that behaves like seamless tubing in sliding and low-pressure sealing, at 40% to 80% lower cost.
Do you manufacture non-circular profiles?
Yes. To EN 10305-5 we manufacture square, oval, flat oval section or whatever section the drawing requires, across all three ranges.
Do you deliver the machined component or just the tubing?
Both. As well as the tubing, we transform the tubing into a finished component ready to assemble: cut, bent, punched, end formed, threaded and machined to drawing.
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Tell us about your application and we'll get back to you in 24 h
We have been manufacturers since 1956. Tell us what you need and our technical team will review your case, with no obligation and no minimum order quantity.
- Technical response in 24 h
- Physical sample to your exact specification
- Cost comparison vs. your current supplier
Prefer to discuss it over the phone? +34 938 424 707