UK HSS Section Properties — CHS, RHS, and SHS Metric Reference Tables
Section properties for UK metric hollow structural sections (HSS) — circular (CHS), rectangular (RHS), and square (SHS) hollow sections — for steel design per EN 1993-1-1 with UK NA. Dimensions, area, second moment of area, elastic and plastic section moduli, radius of gyration, and torsion constants for S275 and S355 steel grades commonly used in UK structural steelwork.
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UK Metric HSS — Section Property Conventions
Hollow structural sections in the UK are manufactured to BS EN 10210-1 (hot-finished) and BS EN 10219-1 (cold-formed). Both are available in S275 and S355 steel grades.
- CHS — Circular Hollow Sections (OD × t)
- RHS — Rectangular Hollow Sections (h × b × t)
- SHS — Square Hollow Sections (b × b × t)
CHS Section Properties (Hot-Finished, S355)
| Designation | OD (mm) | t (mm) | A (cm²) | I (cm⁴) | Wel (cm³) | Wpl (cm³) | i (cm) | It (cm⁴) | Mass (kg/m) |
|---|---|---|---|---|---|---|---|---|---|
| CHS 48.3×4 | 48.3 | 4.0 | 5.56 | 14.3 | 5.9 | 7.8 | 1.61 | 28.6 | 4.37 |
| CHS 60.3×4 | 60.3 | 4.0 | 7.07 | 29.1 | 9.7 | 12.9 | 2.03 | 58.2 | 5.55 |
| CHS 76.1×4 | 76.1 | 4.0 | 9.06 | 59.1 | 15.5 | 20.6 | 2.56 | 118.2 | 7.11 |
| CHS 88.9×5 | 88.9 | 5.0 | 13.2 | 118 | 26.5 | 35.1 | 2.99 | 236 | 10.4 |
| CHS 114.3×5 | 114.3 | 5.0 | 17.2 | 257 | 44.9 | 60.0 | 3.87 | 514 | 13.5 |
| CHS 139.7×6 | 139.7 | 6.0 | 25.1 | 575 | 82.4 | 110 | 4.78 | 1,150 | 19.7 |
| CHS 168.3×6 | 168.3 | 6.0 | 30.6 | 1,026 | 122 | 163 | 5.79 | 2,052 | 24.0 |
| CHS 193.7×8 | 193.7 | 8.0 | 46.5 | 2,038 | 210 | 280 | 6.62 | 4,076 | 36.5 |
| CHS 219.1×8 | 219.1 | 8.0 | 52.9 | 2,971 | 271 | 363 | 7.49 | 5,942 | 41.5 |
| CHS 244.5×10 | 244.5 | 10.0 | 73.7 | 4,981 | 407 | 543 | 8.22 | 9,962 | 57.9 |
| CHS 273×10 | 273 | 10.0 | 82.6 | 7,166 | 525 | 704 | 9.31 | 14,332 | 64.9 |
| CHS 323.9×10 | 323.9 | 10.0 | 98.6 | 12,351 | 763 | 1,025 | 11.2 | 24,702 | 77.4 |
SHS Section Properties (Hot-Finished, S355)
| Designation | b (mm) | t (mm) | A (cm²) | I (cm⁴) | Wel (cm³) | Wpl (cm³) | i (cm) | It (cm⁴) | Mass (kg/m) |
|---|---|---|---|---|---|---|---|---|---|
| SHS 50×5 | 50 | 5.0 | 8.60 | 30.0 | 12.0 | 15.0 | 1.87 | 47.8 | 6.75 |
| SHS 60×5 | 60 | 5.0 | 10.6 | 54.4 | 18.1 | 22.7 | 2.27 | 86.6 | 8.32 |
| SHS 80×5 | 80 | 5.0 | 14.6 | 134 | 33.5 | 41.8 | 3.03 | 213 | 11.5 |
| SHS 100×5 | 100 | 5.0 | 18.6 | 275 | 55.0 | 68.6 | 3.85 | 437 | 14.6 |
| SHS 120×5 | 120 | 5.0 | 22.6 | 499 | 83.2 | 104 | 4.70 | 793 | 17.7 |
| SHS 120×8 | 120 | 8.0 | 33.9 | 683 | 114 | 143 | 4.49 | 1,086 | 26.6 |
| SHS 150×8 | 150 | 8.0 | 43.5 | 1,396 | 186 | 234 | 5.66 | 2,219 | 34.1 |
| SHS 200×10 | 200 | 10.0 | 72.4 | 4,126 | 413 | 518 | 7.55 | 6,555 | 56.8 |
| SHS 250×10 | 250 | 10.0 | 92.4 | 8,656 | 693 | 876 | 9.68 | 13,757 | 72.5 |
RHS Section Properties (Hot-Finished, S355)
| Designation | h×b (mm) | t (mm) | A (cm²) | Iy (cm⁴) | Wel,y (cm³) | Wpl,y (cm³) | iy (cm) | It (cm⁴) | Mass (kg/m) |
|---|---|---|---|---|---|---|---|---|---|
| RHS 100×50×5 | 100×50 | 5 | 13.6 | 170 | 34.0 | 40.2 | 3.54 | 177 | 10.7 |
| RHS 120×60×5 | 120×60 | 5 | 16.6 | 303 | 50.5 | 60.2 | 4.27 | 310 | 13.0 |
| RHS 150×100×6 | 150×100 | 6 | 28.0 | 754 | 101 | 126 | 5.19 | 812 | 22.0 |
| RHS 150×100×8 | 150×100 | 8 | 35.9 | 918 | 122 | 154 | 5.06 | 1,000 | 28.2 |
| RHS 200×100×6 | 200×100 | 6 | 34.0 | 1,746 | 175 | 209 | 7.17 | 1,800 | 26.7 |
| RHS 200×100×10 | 200×100 | 10 | 53.7 | 2,541 | 254 | 317 | 6.88 | 2,760 | 42.2 |
| RHS 250×150×8 | 250×150 | 8 | 59.9 | 4,661 | 373 | 455 | 8.82 | 4,820 | 47.0 |
| RHS 300×200×10 | 300×200 | 10 | 91.7 | 10,900 | 727 | 890 | 10.9 | 11,810 | 72.0 |
| RHS 400×200×12 | 400×200 | 12 | 132 | 26,075 | 1,304 | 1,540 | 14.1 | 26,500 | 104 |
Grade Conversion
Properties are identical for S275 and S355 sections — only the design resistance (fy × Wpl) differs:
- S355: fy = 355 MPa for t ≤ 16 mm; fy = 345 MPa for 16 < t ≤ 40 mm
- S275: fy = 275 MPa for t ≤ 16 mm; fy = 265 MPa for 16 < t ≤ 40 mm
Design Resources
- UK Steel Grades Reference — EN 10025-2 grade selection for UK projects
- UK Steel Mechanical Properties — fy, fu, and elongation tables
- UK Universal Beam and Column Sizes — UB/UC section dimensions and properties
- UK Bolt Capacity Tables — Class 8.8 and 10.9 bolt resistance
- UK Beam Design Guide — EN 1993-1-1 flexure, shear, and LTB
- UK Connection Design Guide — EN 1993-1-8 bolted and welded joints
- All UK Steel Design References — complete library
Frequently Asked Questions
What is the difference between hot-finished and cold-formed HSS?
Hot-finished HSS (BS EN 10210-1) are formed at elevated temperatures and have no residual stresses from cold-forming, giving more favourable buckling curves (a or a0 vs c for cold-formed). Cold-formed HSS (BS EN 10219-1) are formed at room temperature and have higher yield strength in the corners but also higher residual stresses. For structural applications in UK buildings, hot-finished HSS are preferred due to better toughness, weldability, and buckling behaviour. S355 hot-finished HSS uses buckling curve a for flexural buckling (vs curve c for cold-formed).
What is the standard UK HSS grade for structural applications?
S355J2H is the standard UK specification for hot-finished hollow sections to BS EN 10210-1. The H suffix indicates hollow section. S355J2H provides fy = 355 MPa (t ≤ 16 mm) with Charpy 27 J at -20°C. For cold-formed sections to BS EN 10219-1, S355J2H is also standard. S275J2H is a lower-cost alternative for secondary members.
How are HSS properties used in EN 1993-1-1 design?
HSS section properties are used directly in EN 1993-1-1 design checks: Wpl for bending resistance (Mc,Rd), A for axial resistance (Npl,Rd), I and i for buckling checks (λ̄ = Lcr/i × 1/λ1), and It for torsional checks. Hot-finished CHS uses buckling curve a (α = 0.21) for flexural buckling. Hot-finished RHS/SHS uses curve a (S235-S355) or b (S420-S460). CHS has excellent torsional stiffness (It = 2I), making it efficient for torsionally loaded members.
What is the lightweight HSS option for UK construction?
For weight-critical applications, CHS is the most efficient HSS shape for compression members due to its equal buckling strength about all axes and favourable buckling curve a. SHS is efficient for moment connections due to its flat faces. The choice between CHS, SHS, and RHS depends on the connection type — CHS requires specialised connections (slotted gusset or ring stiffeners), while RHS/SHS can use standard bolted connections with fin plates and end plates.
Related Pages
- EN 1993 Steel Design Overview
- European Steel Properties
- EN 1993 Beam Design Guide
- EN 1993 Column Buckling
- EN 1990 Load Combinations
- UK Steel Chemical Composition
- UK Steel Charpy Values
Educational reference only. All design values are per BS EN 1993-1-1:2005 + UK National Annex and BS EN 10025-2:2019. Verify all values against the current editions of the standards and the applicable National Annex for your project jurisdiction. Designs must be independently verified by a Chartered Structural Engineer registered with the Institution of Structural Engineers (IStructE) or the Institution of Civil Engineers (ICE). Results are PRELIMINARY — NOT FOR CONSTRUCTION without independent professional verification.