300×300×18 mm S235JRH Steel Square Hollow Section
300x300x18mm cold-formed ERW square hollow section to EN 10219, rolled in S235JRH, S275J0H or S355J2H depending on size, supplied with a primer-coated surface optimised for paint adhesion.
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
Equal sides carry load about both axes, so this square hollow section is specified for columns, posts, gates, and frames, and the closed section resists torsion better than an open profile of similar weight. Supplied black, with a red-oxide shop primer, or hot-dip galvanized; the internal weld bead can be removed on request on most sizes.
Technical Specifications
| Specification | Value |
|---|---|
| Dimensions | 300mm × 300mm × 18mm |
| Weight per Meter | 148.47 kg/m |
| Material | Steel |
| Alloy/Grade | S235JRH, S275J0H |
| Standard | EN 10219 |
| Finish | Primer Coated |
| 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) | 189 cm² |
| Second moment of area(I) | 23947 cm⁴ |
| Radius of gyration(i) | 11.3 cm |
| Elastic section modulus(Wel) | 1596 cm³ |
| Plastic section modulus(Wpl) | 1943 cm³ |
| Torsional inertia constant(It) | 41665 cm⁴ |
| Torsional modulus constant(Ct) | 2509 cm³ |
| Surface area per metre(As) | 1.11 m²/m |
| Length per tonne | 6.74 m |
Grade strength and capacity
Minimum strength of each grade this size is rolled in, with the indicative capacity of the section.
| Grade | Min. yield | Tensile | Bending Wel·fy | Axial A·fy |
|---|---|---|---|---|
| S235JRH | 225 MPa | 360–510 MPa | 359 kNm | 4256 kN |
| S275J0H | 265 MPa | 410–560 MPa | 423 kNm | 5012 kN |
Ordered in S355J2H, the S235JRH bending capacity of this size is reached with a 10 mm wall in the same outer size (88.4 kg/m, 40% lighter).
Indicative values from nominal dimensions: Wel × fy and A × fy, without buckling, cross-section class or partial safety factors. Not a design check.
Nearest inch size to ASTM A500: HSS 12 × 12 × ¾ →
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