Structural Steel Section Properties Database — 5 Catalogs Compared

A definitive reference covering all five major steel section catalogs used worldwide: AISC W-shapes (US), AS/NZS UB/UC (Australia/NZ), EN IPE/HEA/HEB (Europe), CSA W/WWF (Canada), and UK UB/UC. Includes naming conventions, key properties, and a cross-reference table for equivalent sections.

Overview

Structural steel design begins with section selection, and section selection requires accurate section properties. The five major steel design codes each reference their own catalog of standard hot-rolled shapes. While the sections look similar — they are all I-beams, channels, angles, and hollow sections — the naming conventions, dimensions, tolerances, and property values differ. A W18x35 from the AISC catalog is not exactly the same section as a 460UB67.1 from the Australian catalog, even though both are roughly 18 inches (457 mm) deep.

This guide explains each catalog in detail, provides the key formulas linking section properties, and includes cross-reference tables showing which sections from different catalogs are close equivalents. Understanding these differences matters because using the wrong catalog for your governing design standard produces incorrect results — the section properties (particularly Zx and Ix) differ by 2-8% between nominally-equivalent shapes, and phi factors vary between codes.

The Steel Calculator database contains over 500 sections spanning all five catalogs, with full geometric and derived properties searchable by name, depth, mass, or cross-sectional dimensions.

1. AISC Catalog — US Shapes (AISC Steel Construction Manual, 16th Edition)

The AISC catalog is the reference standard for steel design in the United States, Mexico, and many international projects using US design practice.

Shape Designations

Key Properties (from AISC Table 1-1)

Default Steel Grade

A992 (Fy = 50 ksi, Fu = 65 ksi) for W-shapes. ASTM A36 (Fy = 36 ksi) for angles and plates. ASTM A500 (various grades) for HSS. ASTM A1085 (Fy = 50 ksi) for newer HSS.

2. AS/NZS Catalog — Australian/New Zealand Shapes (AS/NZS 3679.1, OneSteel/InfraBuild)

Shape Designations

Key Properties (from InfraBuild/OneSteel tables)

Default Steel Grade

Grade 300 (fy = 300 MPa, fu = 440 MPa) for standard sections. Grade 350 (fy = 350 MPa, fu = 480 MPa) available for heavier UC sections. Note: fy = 300 MPa = 43.5 ksi — lower than A992's 50 ksi, so an AS section will generally be heavier than a US equivalent for the same capacity.

3. European Catalog — EN Shapes (EN 10365, ArcelorMittal)

Shape Designations

Key Properties

*Note: European convention uses y-y for the strong axis (bending about the major axis). US convention uses x-x. This is a common source of confusion when translating between standards.

Default Steel Grade

S355 (fy = 355 MPa, fu = 470-630 MPa) for standard structural sections per EN 10025-2. S275 (fy = 275 MPa) also common in the UK. Historical S235 (fy = 235 MPa) is still available but rarely used in new construction.

4. CSA Catalog — Canadian Shapes (CSA G40.21, CISC Handbook 11th Ed.)

Shape Designations

Key Properties

Properties follow the same nomenclature as AISC catalog but in SI units (mm, mm^2, 10^6 mm^4, kg/m). Canadian tables are published in the CISC Handbook of Steel Construction.

Default Steel Grade

CSA G40.21 Grade 350W (Fy = 350 MPa, Fu = 450 MPa) for W-shapes. Grade 350A/350AT for atmospheric corrosion-resistant (weathering) steel. Grade 300W used for thicker sections (tf > 50 mm).

5. UK Catalog — British Shapes (BS 4-1:2005, Tata Steel)

Shape Designations

Key Properties

UK sections use the same symbols as European convention (h, b, tw, tf, A, Iy, Wpl,y, iy, It, Iw) in SI units. The UK UB/UC series traces its origin to the same source as the Australian UB/UC, but the actual dimensions differ — UK sections retain imperial-origin dimensions converted to millimetres, while Australian sections were rationalised to metric round values.

Default Steel Grade

S355 J0 or J2 (fy = 355 MPa) per EN 10025-2, with Charpy impact testing (J0 = 0C, J2 = -20C). S275 JR/J0/J2 also widely used. Weathering steel S355 J0W/J2W available.

6. Cross-Reference Table — Equivalent Sections

The following table shows the closest equivalent section in each catalog for common beam sizes. Dimensions may differ by up to 5%; always verify actual properties before substituting.

7. Section Property Relationships and Formulas

Understanding how derived properties relate to geometric dimensions helps verify database values and troubleshoot discrepancies.

Area (I-section):

A = 2 x bf x tf + (d - 2 x tf) x tw + 2 x (1 - pi/4) x r^2

Where r is the fillet radius at the flange-web junction. The fillet term adds 0.2146 x r^2 per corner.

Moment of inertia, strong axis (rectangular approximation, ignoring fillets):

Ix = (bf x d^3 - (bf - tw) x (d - 2 x tf)^3) / 12

This is accurate to within 2% for most hot-rolled sections. The exact value from tables accounts for fillets and tapered flanges.

Plastic section modulus (I-section, strong axis):

Zx = bf x tf x (d - tf) + tw x (d/2 - tf)^2

The first term is the flange contribution (flange area times lever arm between flange centroids), the second term is the web contribution above and below the plastic neutral axis.

Radius of gyration:

rx = sqrt(Ix / A)

Section classification parameters (AISC Table B4.1b):

Flange: lambda = bf / (2 tf)
Web:    lambda = h / tw     (where h = d - 2 k_design)
Compact flange limit: lambda_pf = 0.38 sqrt(E / Fy)
Compact web limit:    lambda_pw = 3.76 sqrt(E / Fy)

8. How to Select the Right Catalog

1. Identify the governing design standard for your project. This is typically determined by the jurisdiction: AISC 360 for US/Latin America, AS 4100 for Australia/NZ, EN 1993 for Europe/UK, CSA S16 for Canada.

2. Use the catalog matching your standard. Each code's phi factors, buckling curves, and interaction equations are calibrated against the steel grades and section tolerances of its native catalog. Mixing catalogs introduces systematic errors.

3. For international projects, the contract typically specifies the governing standard. If none is specified, default to the standard of the country where the structure will be built.

4. For academic work or comparison studies, the Steel Calculator section properties database allows side-by-side property comparison across catalogs. Use this to understand why a W18x35 passes AISC checks but a 460UB67.1 might not pass AS 4100 checks — the differences in both section properties and phi factors combine.

Related Calculators

• Steel Section Properties Database — Browse and search 500+ sections across all 5 catalogs with full properties
• Section Comparison Tool — Side-by-side comparison of section properties from different catalogs
• Moment of Inertia Calculator — Compute section properties for built-up or custom shapes
• Beam Capacity Calculator — Verify member capacity using the correct catalog for your design standard
• Steel Weight Calculator — Quick mass and weight estimates for any section in the database

FAQ

Q: Can I substitute a W-shape for a UB section if the dimensions are close?

A: No — the steel grades differ (A992 Fy = 50 ksi = 345 MPa vs Grade 300 fy = 300 MPa), which means a 15% difference in yield strength. Additionally, AS 4100 and AISC 360 use different buckling curves and interaction equations. A section that passes design checks under one code may fail under another even if the physical dimensions are identical. Always use the catalog that matches your governing standard.

Q: Why do European sections use y-y as the strong axis?

A: European convention (EN 1993) defines the y-y axis as the major (strong) axis of a section, parallel to the flanges. The z-z axis is the minor (weak) axis, parallel to the web. This is the opposite of US/Australian convention where x-x is strong and y-y is weak. When translating section properties between conventions, swap x and y indices: Ix(US) = Iy(EU), Zx(US) = Wpl,y(EU).

Q: What are the closest equivalents between US and European sections?

A: W18x35 ~ IPE450 (within 3% on depth, 8% on Zx). W21x44 ~ IPE500. W14x90 column ~ HEB300. However, flange widths differ significantly: W18x35 has bf = 6.0 in (152 mm) while IPE450 has bf = 190 mm. The European section has 25% wider flanges, giving it higher weak-axis bending capacity and different LTB behavior.

Q: Are UK UB sections the same as Australian UB sections?

A: No — despite sharing the "Universal Beam" name and UB/UC designation system, UK and Australian sections have different dimensions. Both trace their origin to British Standard sections, but Australia rationalised to rounded metric dimensions while the UK retained the original imperial-to-metric conversions. A 460UB67.1 (AU) has d = 454 mm, bf = 190 mm. A 457x191x67 UB (UK) has d = 453.4 mm, bf = 189.9 mm. The differences are small (under 1%) for lighter sections but grow for heavier UC shapes.