Steel Section Properties Database

Search section properties (A, d, bf, tf, tw, Ix, Sx, Zx, rx, ry) for W-shapes, HSS, channels, and angles. All values are from published open-source dimensional data and are provided for educational and preliminary design use. For final design and procurement, verify against the current edition of the AISC Steel Construction Manual, ASI Design Capacity Tables, or ArcelorMittal section catalogs.

Quick access: W12x26 | W14x48 | W18x55 | W30x99 | HSS sections | Beam sizes table

What Are Section Properties?

Every structural steel member has a cross-section defined by its geometry. Section properties are the numerical values derived from that geometry that engineers use to predict how the member will behave under load. Understanding these properties is fundamental to selecting the right beam, column, or brace for any structural application.

The essential section properties are:

Cross-Sectional Area (A) -- the total area of the steel cross-section, measured in in² or mm². Area directly determines axial capacity: a larger area carries more tension or compression force. For a W12x26, A = 7.65 in² (4,935 mm²).

Depth (d) -- the overall depth of the section from the top of the top flange to the bottom of the bottom flange. Critical for floor-to-floor height calculations, connection detailing, and clearance checks. Note that the actual depth often differs from the nominal designation: a W14x48 has an actual depth of 13.8 in, not 14 in.

Flange Width (bf) and Flange Thickness (tf) -- the width and thickness of the top and bottom flanges. Flange dimensions control lateral-torsional buckling resistance, local flange buckling classification, and connection bolt layout. Wider flanges provide greater weak-axis stiffness (higher ry).

Web Thickness (tw) -- the thickness of the vertical plate connecting the two flanges. Web thickness governs shear capacity, web local buckling, and web crippling under concentrated loads.

Moment of Inertia (Ix, Iy) -- also called the second moment of area, measured in in⁴ or mm⁴. Ix (strong axis) and Iy (weak axis) determine how much a beam deflects under load. Higher Ix means less deflection. For a W18x55, Ix = 890 in⁴ and Iy = 44.9 in⁴ -- the strong axis is nearly 20 times stiffer than the weak axis.

Elastic Section Modulus (Sx, Sy) -- calculated as Ix/c, where c is the distance from the neutral axis to the extreme fiber, measured in in³ or mm³. Sx determines the maximum elastic bending stress: fb = M/Sx. Used for serviceability checks and non-compact section capacity.

Plastic Section Modulus (Zx, Zy) -- the sum of first moments of area above and below the plastic neutral axis, measured in in³ or mm³. Zx determines the plastic moment capacity: Mp = Fy x Zx. For compact sections with adequate lateral bracing, the full Mp can be developed. The ratio Zx/Sx (shape factor) is approximately 1.12 for W-shapes, meaning a compact W-shape can carry about 12% more moment than its first-yield capacity.

Radius of Gyration (rx, ry) -- defined as sqrt(I/A), measured in inches or mm. The radius of gyration governs column slenderness (KL/r) and lateral-torsional buckling parameters (Lr, Lp). A higher ry means better resistance to weak-axis buckling.

How to Use Section Properties in Design

Selecting the right section requires matching section properties to design demands. The typical workflow is:

Step 1 -- Estimate loads and determine required strength. Calculate factored moment (Mu), shear (Vu), and axial force (Pu) from load combinations per ASCE 7, AS/NZS 1170, or EN 1990.

Step 2 -- Screen for required Zx (beams) or A (columns). For a simply supported beam, the required plastic modulus is Zx,req = Mu / (phi x Fy). For AISC 360 LRFD with A992 steel (Fy = 50 ksi, phi = 0.90): Zx,req = Mu / (0.90 x 50) = Mu / 45 in-kips. For example, Mu = 250 ft-kips = 3,000 in-kips requires Zx >= 3,000 / 45 = 66.7 in³. A W18x50 (Zx = 101 in³) or W16x31 (Zx = 54.0 in³, too small) can be evaluated.

Step 3 -- Check deflection using Ix. For a simply supported beam under uniform load: delta = 5wL⁴ / (384EI). Deflection limits are typically L/360 for live load (floors) or L/240 for total load. Higher Ix means less deflection. Deflection often controls for long spans, making Ix the governing property rather than Zx.

Step 4 -- Check lateral-torsional buckling using ry and section dimensions. Unbraced length Lb must be compared to Lp and Lr. The plastic bracing limit Lp = 1.76 ry sqrt(E/Fy). For a W18x55 (ry = 1.67 in): Lp = 1.76 x 1.67 x sqrt(29,000/50) = 70.8 in = 5.9 ft. If the beam's compression flange is braced at intervals less than Lp, the full Mp is available.

Step 5 -- Check column slenderness using rx or ry. The slenderness ratio KL/r must be less than 200 per AISC 360. For weak-axis buckling of a W10x49 column (ry = 2.54 in) with K = 1.0 and L = 14 ft: KL/ry = (1.0 x 168) / 2.54 = 66.1 -- well within limits and in the inelastic buckling range where most efficient column designs fall.

W-Shape vs HSS vs Channel vs Angle -- When to Use Each

W-Shapes (Wide-Flange Sections) are the workhorse of structural steel. Two flanges connected by a web create an efficient I-shaped cross-section for resisting bending about the strong axis. W-shapes are the default choice for floor beams, roof girders, and columns. Their open cross-section makes bolted and welded connections straightforward. Typical sizes range from W8x10 (lightest commonly stocked beam) to W44x335 (heavy transfer girders). Available in ASTM A992 (Fy = 50 ksi), which is the current standard for W-shapes, replacing the older A36 designation.

HSS (Hollow Structural Sections) are closed-form square, rectangular, or round tubes. Their closed shape provides excellent torsional resistance (high J) and equal or near-equal stiffness about both axes (for square and round HSS). This makes them ideal for columns, braces, trusses, and exposed architectural members. Square HSS columns eliminate weak-axis concerns since rx = ry. The design wall thickness for ASTM A500 is 0.93 times the nominal thickness due to manufacturing tolerances. See the HSS section properties reference for complete tables.

Channels (C and MC shapes) are single-web sections with flanges on one side only. They are commonly used as stair stringers, wall studs, built-up members (back-to-back channels as columns), and secondary framing. The shear center of a channel does not coincide with the centroid, which causes torsion under transverse loading unless the load passes through the shear center. This must be accounted for in design.

Angles (L-shapes) are single members with two legs at 90 degrees. They are primarily used as braces, truss web members, lintels, shelf angles, and connection elements. Angles have their principal axes rotated relative to the geometric legs, which complicates buckling analysis. For single-angle compression members, AISC 360 Chapter E provides specific provisions for flexural-torsional buckling.

Section Property Tables by Code

Section properties are published in different formats depending on the design code and region:

AISC Steel Construction Manual (US) -- Table 1-1 lists all W-shapes with d, bf, tf, tw, A, Ix, Sx, Zx, Iy, Sy, Zy, rx, ry, J, Cw, and compactness classifications. Properties are in imperial units (in, in², in³, in⁴). The 16th edition (2022) is current.

ASI Design Capacity Tables (Australia) -- Lists UB, UC, and welded sections with metric properties (mm, cm², cm³, cm⁴) plus tabulated design capacities (phi.Ms, phi.Mb, phi.Vv) per AS 4100. The 5th edition references AS 4100:2020.

ArcelorMittal / SCI Blue Book (Europe) -- Lists IPE, HEA, HEB, HEM, UB, UC, and other European series with metric properties and cross-section classification per EN 1993-1-1.

CISC Handbook of Steel Construction (Canada) -- Lists W-shapes with properties identical to AISC (same rolling program) plus Canadian-specific design capacities per CSA S16.

Common W-Shape Section Sizes

The following sections are among the most frequently specified in North American steel construction. Click any section to view its complete property table, design capacity summary, and typical applications.

For the complete 20-section table with all properties, see W-Shape Beam Sizes Reference.

Quick Reference -- W-Shape Properties Summary Table

This table provides the most-searched properties for popular W-shapes at a glance.

Related Calculators

Use section properties from this page as inputs to the following calculators:

• Beam Capacity Calculator -- moment, shear, and LTB checks per AISC 360, AS 4100, EN 1993, or CSA S16
• Column Capacity Calculator -- axial compression capacity with KL/r slenderness checks
• Beam Deflection Calculator -- simply supported and cantilever deflection from Ix
• Moment of Inertia Calculator -- compute Ix, Sx, Zx for custom and built-up sections
• Beam Span Screener -- find the lightest W-shape for a given span and load
• Section Properties Data Sources -- provenance, rounding, and QA notes

Related Reference Tables

• W-Shape Beam Sizes -- Complete Properties
• HSS Section Properties -- Square, Rectangular, Round
• Steel Channel Sizes
• Steel Angle Sizes
• Steel Beam Load Tables
• Steel Grades -- Fy & Fu Reference

Frequently Asked Questions

What is the difference between Sx and Zx? Sx is the elastic section modulus, computed as Ix divided by the distance from the neutral axis to the extreme fiber. It gives the bending stress at first yield: My = Fy x Sx. Zx is the plastic section modulus, which represents the moment at which the entire cross-section has yielded: Mp = Fy x Zx. For W-shapes, Zx is approximately 10-15% larger than Sx (the shape factor). AISC 360 permits using Mp = Fy x Zx as the nominal moment strength for compact sections with adequate lateral bracing.

Why does a W14x48 have a smaller depth than 14 inches? The "14" in W14x48 is a nominal group designation, not the actual depth. The W14 group ranges from 13.7 in (W14x22) to 22.4 in (W14x730). As weight increases within a group, the mill adds material primarily to the flanges, which increases both flange thickness and overall depth. Always use the actual depth (d) from the section property table for design and detailing.

Can I use AISC W-shape properties for Canadian CSA S16 design? Yes. North American W-shapes are produced to the same rolling standards regardless of the design code. The section geometry and properties are identical. What changes is the resistance factor (phi = 0.90 for AISC LRFD vs phi = 0.90 for CSA S16 -- coincidentally the same for flexure) and the specific capacity equations.

What steel grade should I assume for W-shapes? ASTM A992 is the current standard for W-shapes in the United States, with Fy = 50 ksi and Fu = 65 ksi. A992 replaced A36 (Fy = 36 ksi) and A572 Gr. 50 as the default W-shape material starting in 1998. In Australia, Grade 300 (Fy = 300 MPa) is standard for UB/UC sections per AS/NZS 3679.1.

How do I convert between imperial and metric section properties? Area: 1 in² = 645.16 mm². Moment of inertia: 1 in⁴ = 416,231 mm⁴. Section modulus: 1 in³ = 16,387 mm³. Depth/width: 1 in = 25.4 mm. Keep full precision in conversions and round only for display.

Where do I find torsional properties (J, Cw)? Torsional constant J and warping constant Cw are listed in AISC Table 1-1 but are not included in the quick-reference tables above. They are needed for lateral-torsional buckling calculations (Lr depends on J and Cw) and for checking torsion per AISC Design Guide 9. Use the individual section pages or the AISC Manual for these values.

Disclaimer (educational use only)

This page is provided for general technical information and educational use only. It does not constitute professional engineering advice, a design service, or a substitute for an independent review by a qualified structural engineer. Any calculations, outputs, examples, and workflows discussed here are simplified descriptions intended to support understanding and preliminary estimation.

All real-world structural design depends on project-specific factors (loads, combinations, stability, detailing, fabrication, erection, tolerances, site conditions, and the governing standard and project specification). You are responsible for verifying inputs, validating results with an independent method, checking constructability and code compliance, and obtaining professional sign-off where required.

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