European Steel Sections Calculator — Section Properties, Unity Checks & LTB (EN 1993-1-1)

Cross-section resistance checks (bending, shear, axial, shear-moment interaction and M-N interaction) follow EN 1993-1-1:2005 (Eurocode 3, Part 1-1), §6.2; when the shear exceeds half the plastic shear resistance, the combined M-N check uses the shear-reduced moment and axial resistances of §6.2.10. Section classification uses §5.5 and Table 5.2 — sheet 2 outstand limits for I/H flanges, sheet 1 internal-part limits for the webs and for both walls of a rectangular or square hollow section (a web in bending uses 72ε / 83ε / 124ε; under axial compression its limits come from the plastic compression-zone ratio α and the elastic stress ratio ψ — the stricter of the reading for N_Ed and the actual N:M distribution — reaching 33ε / 38ε / 42ε for a column with no moment, so a slender web such as IPE 600 in S460 becomes Class 3 or Class 4 as N_Ed rises; a Class 4 section returns NO RESULT unless a check on the gross section already fails, which the effective section could not improve), and sheet 3 (d/t against 50ε² / 70ε² / 90ε²) for circular hollow sections. Lateral-torsional buckling is evaluated to §6.3.2.2, the general case (buckling curve b, α_LT = 0.34). With axial compression and bending together, §6.3.3 is checked as a conservative upper bound of Eq. 6.61 / 6.62 by Method 2 (Annex B with C_my = C_mLT = 1, buckling curve c on both axes); member buckling on its own (§6.3.1) is indicative only — flexural about the smaller radius of gyration and, for I-sections, torsional (§6.3.1.4), whichever reduces more; a cantilever I-section whose torsional or lateral-torsional buckling check passes only with a base that prevents warping reads NO RESULT. The deflection check uses standard elastic beam theory for the chosen support condition and is compared to an L/300 target — note that EN 1993-1-1 §7.2 and EN 1990 A1.4 leave deflection limits to the National Annex and to project agreement, so L/300 is a common default rather than a code requirement. γ_M0 = γ_M1 = 1.0 and γ_M2 = 1.25 are recommended values and are Nationally Determined Parameters. The governing standard and clause references are shown in the generated PDF report.

174 European profiles: hot-rolled I-profiles (IPE, HEA, HEB) plus rectangular, square and circular hollow sections (RHS, SHS, CHS). The I/H profile properties are the EN 10365 tabulated values, except the torsion constant I_t, which is computed from the nominal dimensions. The hollow sections are computed from their EN 10210-2 / EN 10219-2 designation — h × b × t, depth first — including the EN 10219-2 cold-formed corner radii, which brings their areas and masses to within 0.1 % of catalogue (SHS 200×8 gives 59.24 cm² and 46.5 kg/m). American AISC W and S shapes are deliberately NOT in this tool: a W-shape is designed to AISC 360 with an ASTM grade such as A992 (Fy = 50 ksi), not to EN 1993-1-1 with S235, so checking one here would mix two codes. AISC section properties are available in the Reference Library, which is a lookup and applies no design code. Every computed row is labelled as such in the tool; check against the producer catalogue before final design. The full library is searchable and filterable by profile type in the "Section library" section at the foot of the page.

Yes — for open I/H-sections (IPE, HEA and HEB) the LTB check is performed per EN 1993-1-1 §6.3.2.2. Enter the laterally unrestrained length L_cr, or tick the fully-restrained option if decking, a slab or bracing restrains the compression flange continuously, in which case §6.3.2 is not applied. The tool computes the elastic critical moment M_cr from the section torsional and warping properties (for a cantilever whose base is free to warp, from the torsional and weak-axis stiffness alone) and the load position — top flange by default, which lowers M_cr; shear centre; or hung from the bottom flange, taken at the shear centre — the non-dimensional slenderness λ̄_LT, the χ_LT reduction factor (curve b) and the design buckling moment resistance M_b,Rd. A cantilever is read with its base both preventing and free to warp, and a moment typed in by hand on a cantilever is taken as uniform (the most onerous case). For closed hollow sections (RHS, SHS, CHS) the torsional stiffness makes lateral-torsional buckling non-critical in normal building cases, so the cross-section resistance governs directly and no LTB check is reported.

No — it detects when the check is required and then withholds the verdict. EN 1993-1-1 §6.2.6(6) sends a web to the EN 1993-1-5 §5 shear-buckling check when h_w/t_w > 72ε/η; the tool takes η = 1.2, the EN 1993-1-5 recommended value up to S460, which puts the limit at 60ε (the conservative reading for this limit). In the library that applies to IPE 400 and IPE 450 in S460 and to IPE 500, 550 and 600 in S420 and S460. While such a web carries shear the tool returns NO RESULT instead of a verdict based on the plastic shear resistance V_pl,Rd, which the web may not reach — unless a check already fails, in which case the FAIL stands. Verify those webs to EN 1993-1-5 §5 separately.

Yes, for I/H sections — the resistance of the web to transverse forces to EN 1993-1-5 §6 (patch loading and web crippling), under the point load and at bearing end supports, with the §7.2 interaction with bending at the point load; it joins the one governing utilisation. Enter the stiff bearing length under the load and at the supports; left blank, a knife-edge bearing (s_s = 0) is assumed and labelled; if the web fails only on that assumption the result reads CONFIRM — web bearing not verified, with the utilisation at s_s = 0 — rather than FAIL, until you enter the length. The web is taken as unstiffened. Fixed ends, a cantilever root and reactions carried by web connections (end plates, cleats — EN 1993-1-8) are not checked as flange bearings, and hollow sections are not checked for transverse forces; the tool says so wherever it applies.

Yes — open the "Compare sections" section and select up to three profiles. It shows a radar chart normalised to the maximum in each property (Iy, Iz, Wy,el, height, mass), a side-by-side property table, an efficiency index (Wy,el / mass) to identify the most material-efficient profile for your load case, and the M-N interaction diagram for the currently selected section. A separate "Shape efficiency at equal area" section ranks the generic forms — solid square and round, square and round hollow, I-section and channel — at one cross-sectional area, using the second moment of area for bending, the radius of gyration for axial load and the St-Venant torsion constant for torsion.

Yes — the Steel Sections tool is fully free with no login required. You can access section properties and all EN 1993-1-1 checks immediately. A free 30-minute preview of the wider MechanixCalc suite is available with no sign-up, and a free 14-day account trial (no credit card required) unlocks every paid calculator. The branded PDF engineering report and saved calculations are included in the free 14-day trial and in every paid plan.