350×350×9 mm S420MC–S700MC High-Strength Square Hollow Section
350x350x9mm Steel high-strength square tube in S420MC, S500MC, S600MC, S700MC to EN 10219 / EN 10149-2, with an uncoated steel surface suitable for further processing or painting. Nominal weight 94.183 kg/m.
Minimum order
Minimum 10 t per size. If the size is already in the current production cycle, we can accept orders from 5 t. Standard length 6 m; 4–12 m on request. We confirm the minimum, lead time and grade in your quote.
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Minimum order: 10 t per size (from 5 t if the size is in production)
Applications & Usage
This extra heavy-duty industrial Steel high-strength square tube is commonly specified for heavy structural supports, load-bearing frames, and demanding industrial applications. The 9mm wall thickness provides exceptional structural integrity while maintaining workability. The natural mill finish provides a cost-effective solution for applications where aesthetics are secondary. Available in standard lengths of 6m, this profile can be easily cut, drilled, and welded to suit your specific requirements.
Technical Specifications
| Specification | Value |
|---|---|
| Dimensions | 350mm × 350mm × 9mm |
| Weight per Meter | 94.183 kg/m |
| Material | Steel |
| Alloy/Grade | S420MC, S500MC, S600MC, S700MC |
| Standard | EN 10219 / EN 10149-2 |
| Standard Length | 6m |
| Minimum Order per Size | 10 t |
| Cut-to-Length Range | 4000 – 12000 mm |
Section Properties
Nominal values calculated from nominal dimensions to EN 10219-2.
| Property | Value |
|---|---|
| Cross-sectional area(A) | 120 cm² |
| Second moment of area(I) | 22967 cm⁴ |
| Radius of gyration(i) | 13.8 cm |
| Elastic section modulus(Wel) | 1312 cm³ |
| Plastic section modulus(Wpl) | 1522 cm³ |
| Torsional inertia constant(It) | 36372 cm⁴ |
| Torsional modulus constant(Ct) | 1987 cm³ |
| Surface area per metre(As) | 1.36 m²/m |
| Length per tonne | 10.6 m |
High-strength grades for this size
Strength and indicative capacity for each grade this size is rolled in, compared with the S355J2H wall that carries the same bending load in the same outer size.
| Grade | Min. yield ReH | Tensile Rm | Bending Wel·ReH | Axial A·ReH | S355J2H equivalent |
|---|---|---|---|---|---|
| S420MC | 420 MPa | 480–620 MPa | 551 kNm | 5039 kN | 12 mm · 123 kg/m (+30%) |
| S500MC | 500 MPa | 550–700 MPa | 656 kNm | 5999 kN | 14 mm · 141 kg/m (+50%) |
| S600MC | 600 MPa | 650–820 MPa | 787 kNm | 7199 kN | Beyond the S355J2H range of this size |
| S700MC | 700 MPa | 750–950 MPa | 919 kNm | 8399 kN | Beyond the S355J2H range of this size |
In S500MC, this section (94.2 kg/m) carries the elastic bending load of a 14 mm S355J2H wall in the same outer size (141 kg/m), which is 50% heavier per metre. In S700MC, this section carries more elastic bending load than any S355J2H wall rolled in the same outer size; matching it in S355 needs a larger section.
Indicative values from nominal dimensions: Wel × ReH and A × ReH, without buckling, cross-section class or partial safety factors. Not a design check.
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