Bebbington Engineering Studio Ltd
← Resource Centre

Tool

Steel Section Capacity Checker

Preliminary verification of a steel section you have already selected. Choose the section, enter the loading and the tool reports bending, shear, deflection, web bearing, web crushing and an approximate lateral-torsional buckling check, together with the governing criterion and reserve capacity.

Engineering basis: Eurocode 3 — BS EN 1993-1-1 with the UK National Annex. Version 1.0 · Reviewed August 2026.

Section properties — 406x178x60 UB

Depth h
406.4 mm
Width b
177.9 mm
Area A
76.6 cm²
Mass
60.1 kg/m
Second moment Iy
21600 cm⁴
Elastic modulus Wel,y
1063 cm³
Plastic modulus Wpl,y
1200 cm³
Radius of gyration iy
16.8 cm
Radius of gyration iz
4.0 cm

Section data source: Section properties compiled from SCI publication P363 (Blue Book), Eurocode edition, and BS EN 10210 for hot-finished hollow sections. Values are nominal and provided for preliminary sizing only. Area, elastic modulus and radii of gyration are derived from the published mass and second moments.

Output

Select a section, enter the loading and press Check section.

Tool version 1.0 · Last reviewed August 2026

Method and assumptions
  • · Support reactions, maximum shear and maximum moment are derived from standard simply supported or cantilever formulae.
  • · Bending resistance Mpl,Rd = Wpl,y fy / γM0; elastic bending stress is reported as MEd / Wel,y.
  • · Shear resistance Vpl,Rd = Av fy / (√3 γM0), with Av taken as h·tw for open sections, A·h/(h+b) for RHS and SHS and 2A/π for CHS.
  • · Deflection is compared with the selected span-based limit (L/180 to L/500).
  • · Where a section fails, the three lightest heavier sections that satisfy every check are suggested for comparison.

Worked example

  • 406x178x60 UB, S275, 6.0 m simply supported span, Gk = 10 kN/m, Qk = 8 kN/m, L/360, unrestrained.
  • wULS = 1.35 × 10 + 1.5 × 8 = 25.5 kN/m → MEd = 25.5 × 6² / 8 ≈ 115 kNm, VEd ≈ 76 kN.
  • Mpl,Rd = 1200 × 10³ × 275 / 10⁶ ≈ 330 kNm — the approximate LTB check typically governs when the flange is unrestrained.
Engineering assumptions and limitations
  • · Eurocode basis — BS EN 1993-1-1 with the UK National Annex; partial factors γM0 = γM1 = 1.0.
  • · Loads are combined at ULS as 1.35 Gk + 1.5 Qk (EN 1990, expression 6.10); deflection uses unfactored load.
  • · Linear elastic serviceability behaviour; no allowance for creep, pre-camber or construction sequence.
  • · Class 1 or 2 cross-section assumed for the plastic bending resistance — section classification must be verified.
  • · Web bearing and web crushing use simplified effective-length approaches and ignore stiffeners.
  • · Lateral-torsional buckling is approximate: uniform moment, kz = kw = 1 and C1 = 1.0.
  • · Preliminary assessment only — no fire design, no connection design, no vibration assessment, no fatigue assessment.
  • · Final member suitability requires full structural appraisal by a Chartered Structural Engineer.

Disclaimer

Indicative result only. The calculation depends on the assumptions and information entered and does not constitute structural design or professional advice. Do not use the result for construction, procurement, Building Regulations submissions or safety-critical decisions. All results must be independently verified by a suitably qualified structural engineer before being used for design, construction or regulatory purposes. Bebbington Engineering Studio Ltd accepts no responsibility for reliance placed on unverified results.