Section Classification Tool

Enter the overall dimensions of a symmetric I/H-shaped section, its steel grade, and the loading condition, to determine its cross-section classification (Class 1–4) per Eurocode 3. This tells you whether the section can reach full plastic capacity, or whether local buckling limits it to a lower strength.

Standards used on this page

  • BS EN 1993-1-1:2005+A1:2014 (Eurocode 3, Part 1-1) — Table 5.2, maximum width-to-thickness ratios for compression parts
  • BS EN 10025-2, Table 7 — yield strength by nominal element thickness
  • UK National Annex to BS EN 1993-1-1
Scope of this tool: covers pure bending OR pure axial compression only. A column carrying both an axial load and a bending moment at the same time needs a combined check — the Column Buckling Module offers a simplified approximation for this case.
Note on accuracy: as with the Section Property Module, this tool assumes sharp (unfilleted) corners where the web meets the flanges, and calculates yield strength separately for the flange and web based on their own thickness, per BS EN 10025-2.
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Disclaimer: This tool provides preliminary, indicative classification checks only. It is not a substitute for verification by a qualified structural engineer. cad-steel.co.uk accepts no liability for designs based solely on these results. Always have final designs checked and signed off by a suitably qualified and experienced structural engineer before construction.