SSAB Domex Tube 500MH
Selecting and fabricating the SSAB hollow-section product with its mechanical-test and design-scope limits intact.
Tags: materials, steel, hollow-sections, producer-products
On this page
Product identity and ordering
SSAB's Domex Tube 500MH minimum A5 elongation of 15% drops by two percentage points when (B + H)/(2T) < 12.5 for square or rectangular sections, or D/T < 15 for round sections. A hypothetical 100 × 100 × 10 mm square gives (100 + 100)/(2 × 10) = 10, so the adjusted minimum is 13%. Confirm availability separately. SSAB applies impact testing at ≥6 mm wall. Check the actual test record. SSAB 500MH test footnotes
SSAB Domex Tube 500MH is a producer-specific structural hollow-section product. SSAB's tube product group lists circular sections from 42.4 to 323.9 mm, square sections from 40 × 40 to 300 × 300 mm, rectangular sections from 50 × 30 to 400 × 200 mm, and a wall-thickness envelope of 2.0–12.5 mm. These envelopes do not mean every size/wall combination is available. Check the detailed offer and order confirmation. SSAB: tubes product group
The tube-group entry identifies EN 10219-2 and EN 1090-2 for this product. Confirm the applicable standards and editions in the contract and delivered documentation rather than treating a family listing as proof of certification for an unidentified stock item. SSAB: product-group standards listing
Mechanical properties and footnotes
The current Tube 500MH page states these values:
| Property | Product-page requirement |
|---|---|
| Rp0.2 proof strength | Minimum 500 MPa |
| Tensile strength Rm | 580–760 MPa |
| Elongation A5 | Minimum 15%, subject to section-proportion footnote |
| Charpy-V energy | 27 J at −40 °C, referenced to a 10 × 10 mm specimen |
For rectangular sections, SSAB tests mechanical properties on the longer side. The elongation minimum is reduced by two percentage points when D/T < 15 for round sections or (B + H)/(2T) < 12.5 for rectangular/square sections. Impact testing under EN ISO 148-1 is performed on wall thicknesses ≥6 mm; the specified minimum corresponds to a full-size specimen. Do not infer a full-size test on every thin-wall tube. SSAB: Tube 500MH properties and footnotes
Product standard versus structural design
SSAB's Domex Tube Structural Hollow Sections, EN 1993 handbook, 2016 edition is useful background, but its introduction explicitly limits the principal design provisions to S235–S460 under EN 10219:2006. It describes S500–S550 as anticipated in the then-forthcoming draft revision. Do not use that historical handbook as blanket confirmation that every S500 member or connection satisfies the currently applicable design rules. SSAB: 2016 handbook, section 1.1
For a load-bearing application, identify the governing design standard and its coverage of the ordered grade. Check section classification, local and overall buckling, effective lengths, joint resistance, serviceability and fatigue as applicable. Higher proof strength does not proportionally reduce deflection or remove geometric-instability limits. Use the actual section properties and tolerances, including corner geometry and wall thickness, rather than modeling a hollow section as a sharp-cornered ideal box without review.
A useful calculation record distinguishes the material requirement from nominal-section properties, characteristic resistance and final design resistance. Preserve the safety factors and applicability conditions of each method.
Fabrication and corner regions
The 2016 handbook explains that SSAB Domex tubes are cold-formed and discusses welding in and near their corners against EN 1993-1-8 conditions. That is producer/product guidance tied to a particular standards framework; retain its conditions and confirm applicability to the ordered 500MH product and current design basis. It is not permission to ignore joint design, welding procedure or inspection. SSAB: handbook, corner-region welding discussion
Before fabrication, obtain current producer guidance for welding, bending, thermal cutting, heat exposure and coating treatment. Use the delivered analysis and appropriate weldability information when qualifying the procedure. Define filler selection, hydrogen control, preheat/interpass requirements and heat input for the actual joint, thickness and restraint; this page supplies no universal settings.
Inspect seam location and accessibility when laying out holes, attachments and connections. Check cut quality, fit-up and distortion against the drawing, and retain traceability when tubes are cut into shorter pieces. A mill tensile result cannot qualify a subsequently bent or welded assembly by itself.
Fatigue, surface condition and storage
SSAB's fatigue guidance explains that welded-joint performance depends strongly on weld geometry, imperfections and residual stresses, so improved base-material strength does not automatically produce the same improvement in the welded detail. Locate attachment ends and weld starts/stops with the stress distribution in mind, and assess the actual load spectrum. The cited page discusses trailer design; its examples are explanatory rather than ready-made hollow-section design capacities. SSAB: fatigue design guidance
SSAB's technical article on hollow sections also highlights surface condition and proper storage in fatigue applications. Its illustrated research comparison concerns 100 × 100 × 5 mm sections and includes an internally corroded cold-formed specimen. This is evidence that condition and test configuration matter, not a universal fatigue-life advantage for every cold-formed product. SSAB: hollow sections for functional design, fatigue discussion
Specify corrosion protection, drainage and sealing details for the intended environment. Include the inside of a hollow section where moisture or process fluids can enter, and inspect damage or contamination before coating and assembly.
Purchase and release record
Retain:
- Exact product, shape, dimensions, wall and delivery requirements.
- Governing specifications, editions and required certificate/traceability.
- Test values with specimen basis and applicable footnotes.
- Structural design basis and grade coverage for members and joints.
- Fabrication procedures, heat/coating exposure and inspection results.
- Fatigue, corrosion-protection and in-service inspection requirements.
The handbook is explicitly dated 2016. The cited current product pages and technical article do not establish clear printed revision dates; obtain controlled current documentation for procurement. This page's review date records source review, not an edition of a product standard or proof of delivered provenance.