S355J0 HEB 340x300x12x21.5 H Beam is a European medium-series wide-flange structural section. It has a height of 340 mm, flange width of 300 mm, web thickness of 12 mm and flange thickness of 21.5 mm. Its standard designation is HEB 340.
The profile weighs approximately 134 kg/m and has a cross-sectional area of approximately 171 cm². Its thick flanges and broad 300 mm width give the S355J0 HEB 340 Steel Profile good bending stiffness, compression resistance, and connection capacity. It is therefore frequently selected for main building frames, heavy columns, transfer beams and equipment-support structures.
What Does 340x300x12x21.5 Mean?
The numbers in S355J0 HEB 340x300x12x21.5 wide flange H beam describe its principal section dimensions:
| Mark | Meaning | Dimension |
|---|---|---|
| h | Overall section height | 340 mm |
| b | Flange width | 300 mm |
| tw | Web thickness | 12 mm |
| tf | Flange thickness | 21.5 mm |
The 12 mm web mainly transfers shear forces between the two flanges, while the 21.5 mm flanges provide most of the resistance to bending. The 300 mm flange width also offers a practical contact surface for base plates, end plates, stiffeners and high-strength bolted connections.
Technical Specification of S355J0 HEB 340 H Profile Steel
The section dimensions of S355J0 HEB 340 H Profile Steel are generally specified according to EN 10365. Dimensional and shape tolerances are controlled according to EN 10034, while surface condition can be inspected according to EN 10163-3.
| Technical Item | Specification |
|---|---|
| Product | European wide-flange H beam |
| Section designation | HEB 340 / HE 340 B |
| Complete dimensions | 340×300×12×21.5 mm |
| Material grade | S355J0 |
| Material standard | EN 10025-2 |
| Section standard | EN 10365 |
| Dimensional tolerance | EN 10034 |
| Surface standard | EN 10163-3 |
| Root radius | Approx. 27 mm |
| Clear web depth | Approx. 243 mm |
| Cross-sectional area | Approx. 171 cm² |
| Theoretical weight | Approx. 134 kg/m |
| Surface area | Approx. 1.81 m²/m |
| Common lengths | 6 m and 12 m |
| Customized length | Available according to project |
The dimensional values agree with published European HEB section tables. Buyers should nevertheless confirm the ordered standard, allowable tolerances and actual length before production.
How Strong Is S355J0 HEB 340x300x12x21.5 H Beam?
The HEB 340 section has a strong-axis moment of inertia of approximately 36,660 cm⁴ and an elastic section modulus of approximately 2,156 cm³. These values indicate that the profile provides substantially greater bending stiffness than smaller HEB sizes.
| Section Property | Approximate Value |
|---|---|
| Strong-axis moment of inertia, Ix | 36,660 cm⁴ |
| Strong-axis elastic modulus, Wx | 2,156 cm³ |
| Strong-axis plastic modulus, Wpl,x | 2,408 cm³ |
| Weak-axis moment of inertia, Iy | 9,690 cm⁴ |
| Weak-axis elastic modulus, Wy | 646 cm³ |
| Weak-axis plastic modulus, Wpl,y | 985 cm³ |
| Strong-axis radius of gyration, ix | 14.65 cm |
| Weak-axis radius of gyration, iy | 7.53 cm |
These are geometric section properties, not a direct statement of safe load capacity. The actual resistance of the S355J0 HEB 340x300x12x21.5 H Beam depends on span, effective length, lateral restraint, section classification, buckling, connection design and load combination.
Mechanical Properties of S355J0 HEB 340 Steel Profile
S355J0 is a weldable structural steel manufactured according to EN 10025-2. Because the HEB 340 flange is 21.5 mm thick, its mechanical properties should be selected from the thickness range above 16 mm and up to 40 mm.
| Mechanical Property | Requirement |
|---|---|
| Minimum yield strength | 345 MPa |
| Tensile strength | 470–630 MPa |
| Minimum elongation | 22% |
| Charpy V-notch impact energy | Minimum 27 J at 0°C |
Although the grade name contains "S355," the guaranteed yield strength decreases with material thickness. For the 21.5 mm flange, the minimum yield strength used for verification is normally 345 MPa rather than 355 MPa.
Chemical Composition of S355J0 HEB 340 H Beam
The controlled carbon and manganese contents of S355J0 help the material maintain a useful balance between strength, toughness and weldability.
| Element | Maximum Content (%) |
|---|---|
| Carbon, C | 0.22 |
| Silicon, Si | 0.55 |
| Manganese, Mn | 1.60 |
| Phosphorus, P | 0.035 |
| Sulfur, S | 0.035 |
| Nitrogen, N | 0.012 |
| Copper, Cu | 0.55 |
The table gives general reference limits. The actual heat analysis, carbon equivalent and mechanical-test results must be checked against the EN 10204 3.1 mill test certificate supplied with the material.
S355J0 HEB 340 Weight and Purchasing Calculation
The theoretical unit weight of the S355J0 HEB 340x300x12x21.5 H Beam is approximately 134 kg/m.
| Beam Length | Theoretical Weight per Piece |
|---|---|
| 6 m | Approx. 804 kg |
| 9 m | Approx. 1,206 kg |
| 12 m | Approx. 1,608 kg |
| 15 m | Approx. 2,010 kg |
| 18 m | Approx. 2,412 kg |
The theoretical order weight can be estimated using:
Total weight = 134 kg/m × length × number of pieces
For example, 20 pieces with a length of 12 m have a theoretical total weight of approximately 32.16 tonnes. The final commercial weight should follow the agreed theoretical-weight or actual-weighing method and the applicable rolling tolerance.
Fabrication and Inspection of S355J0 HEB 340 H Beam
The S355J0 HEB 340 H Beam can be supplied in full mill lengths or processed according to fabrication drawings. Available work includes fixed-length sawing, flange and web drilling, coping, beveling, stiffener welding, end-plate assembly, base-plate assembly, shot blasting, painting and hot-dip galvanizing.
For outdoor construction, a suitable corrosion-protection system should be specified because S355J0 is conventional structural steel rather than weathering steel. Welding procedures should also consider the actual carbon equivalent, flange thickness, joint restraint and ambient temperature.
Inspection should cover both material traceability and finished-component accuracy. The heat number should correspond with the EN 10204 3.1 certificate, while dimensions, straightness, surface condition, hole position and fabricated-component tolerances should be checked before shipment. SGS, BV or another nominated third party can be arranged when the project requires independent verification.
Where Is S355J0 HEB 340x300x12x21.5 H Beam Used?
The combination of a deep section, broad flanges and S355J0 material makes this profile suitable for industrial workshop columns, warehouse main frames, transfer beams, equipment platforms, crane-support structures, pipe racks and heavy commercial-building frames.
For columns, the broad flange improves stability and provides space for base-plate connections. For beams, the high strong-axis inertia helps control bending deformation. In fabricated frames, the thick flanges also provide a practical connection area for end plates, stiffeners and high-strength bolts.
The actual application must still be confirmed by a structural engineer according to load, span, buckling length, connection arrangement and local construction standards.
We supply S355J0 HEB 340x300x12x21.5 H Beam in standard and customized lengths, with optional cutting, drilling, welding, blasting, coating, galvanizing and third-party inspection.
Request a Quote for S355J0 HEB 340 H Beam
To obtain a project-specific quotation, please send us the required length, number of pieces, total tonnage, processing drawings, surface-protection requirements, certificate requirements and destination port.
We can provide specification confirmation, theoretical weight calculation, processing recommendations, loading plans and FOB, CFR, CIF or DDP pricing.
