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Seamless Tubes

Without a weld seam, there is no seam zone to account for in design or processing. Our seamless tubes cover structural steelwork, mechanical engineering, machined components and pressure applications, from 13.5 to 610 mm outside diameter, and arrive with an EN 10204 3.1 inspection certificate, so the material documentation is in place before the first cut.

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01Performance & features

Qualities that carry through to the finished part

From the frame of a steel structure to a turned machine component, the same properties decide how a tube behaves in your workshop and in service.

Easy to process

Readily weldable and straightforward to cut and machine, so the tube fits into the processes your workshop already runs.

Dimensionally stable

High dimensional stability and a homogeneous structure keep the tube true to size, which can reduce adjustment work in assembly.

Highly concentric

A bore that sits true to the outer diameter gives turned and bored parts a reliable starting point for machining.

Strong static properties

Structural grades to EN 10210 give load-bearing members in steel construction a defined and documented performance basis.

02Round tubes

Standards, grades and dimensions

One section family, from standard structural grades to high-strength steels. Choose the grade by load case, then specify the size your design calls for.

PropertyValueStandard
Outside diameter13.5 – 610 mm-
Wall thickness2 – 100 mm-
Structural tubesS235JRH · S355J2HEN 10210
Mechanical engineeringE235+AR · E355+AR · E355+NEN 10297-1
Machining purposes20MnV6 · E470ISO 2938 / EN 10294-1
Pressure purposesP235TR1 · P235TR2 · P355N · P355NH TC1EN 10216-1 / EN 10216-3
Inspection certificate3.1 to EN 10204 (3.2 on request)EN 10204
CE markingfor structural tubes-

Ask our steel team to confirm the combination of grade, outside diameter and wall thickness your project requires.

03 - Seamless steel tubes

What are seamless steel tubes?

Seamless steel tubes are made without a longitudinal weld seam. A solid steel billet is worked into a tubular shape by plastic deformation, and depending on the production route the tube is then rolled or cold-drawn to reach its final dimensions and properties.

Because there is no seam, seamless tubes suit applications in which defined mechanical properties, product uniformity and operational reliability matter most. Which tube fits still depends on the application, the steel grade, the standard and the service conditions.

ALUKÖNIGSTAHL supplies seamless tubes for structural and mechanical applications, precision tubes, and solutions for specific piping applications.
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04Types of seamless tubes

Four tube groups, each with its own job

The application decides the group, and the group decides the standard, the grade and the documentation you specify.

Structural tubes

Structural tubes

For steel structures, machinery and equipment.

Mechanical tubes

Mechanical tubes

For parts and components that need specific material properties.

Precision tubes

Precision tubes

For high dimensional accuracy and surface quality.

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Tubes for pressure purposes

Tubes for pressure purposes

For conveying specific media, chosen by standard and project requirements.

05 - Applications

Where seamless tubes are specified

Seamless tubes carry loads and transmit forces across many industries. Depending on grade and specification, they also serve in demanding mechanical and hydraulic systems.

  • Mechanical engineering
  • Equipment manufacturing
  • Steel construction
  • Transportation engineering
  • Selected industrial installations
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06Quality & documentation

Which certificates come with seamless tubes?

For industrial applications, material traceability and quality documentation are essential. Seamless tubes come with an EN 10204 type 3.1 inspection certificate, and with a type 3.2 inspection certificate on request, subject to the conditions that apply to the relevant product group.

A tube without a weld seam is not automatically suitable for pressure applications. Its suitability depends on meeting the specific requirements of the intended application.

07Selection

How to select a seamless tube

Define these points in your enquiry:

  1. 01

    Dimensions

    Outside diameter and wall thickness

  2. 02

    Grade

    Steel grade and required mechanical properties

  3. 03

    Standard

    Product standard and delivery condition

  4. 04

    Service Conditions

    Service conditions such as temperature, pressure and load type

  5. 05

    Certification

    Inspection certificates and additional testing

Not sure which tube fits your application?

Tell us the load case, the processing steps and the documentation your project requires. Our steel specialists compare grades and dimensions with you, so the order you place is the one your project needs.

Contact a specialist