AISC v16.0 · W shape

W18X311

W18X311 weighs 311 lb/ft, has a depth of 22.3 in, a cross-sectional area of 91.6 in², and an x-axis elastic section modulus Sx of 624 in³. Open the full US customary property record or generate 2D, data, report, and 3D reference files locally in your browser.

W 311 lb/ft · 91.6 in² · EDI W18X311

Choose a download Use in calculators Back to shape search

Nominal profile Units · inches

Building nominal profile…

Weight: 311 lb/ft
Area: 91.6 in²
Depth: 22.3 in
Elastic Sx: 624 in³

From designation to geometry

Reading the W18X311 record

The 18 in depth series in W18X311 is a designation. The tabulated depth d is 22.3 in and flange width bf is 12 in. The separately listed detailing depth ddet is 22.375 in.

The web thickness tw is 1.52 in and flange thickness tf is 2.74 in. Keep the exact designation with these dimensions: matching the depth series does not guarantee matching flanges, web geometry or connection fit.

Ix = 6,970 in⁴ and Iy = 795 in⁴ refer to the database x- and y-axes. Here Ix is numerically larger. Axis letters are labels, not a guarantee that x is always the larger axis. These are geometric properties, not allowable loads or complete member capacities.

Match the axis and dimension conventions to the figures in the AISC v16.0 workbook Readme. The profile above simplifies manufacturing geometry; its outline is not used to recalculate the published properties.

Worked quantity example

Nominal weight for W18X311

Assume 3 pieces, each 20 ft (6.096 m) long. This is a hypothetical quantity example, not a stock-length or lifting recommendation.

Using the published 311 lb/ft weight
Quantity	Calculation	Nominal pounds	Kilogram equivalent
One 20 ft piece	20 ft × 311 lb/ft	6,220 lb	2,821.345 kg
3 pieces	3 × 6,220 lb	18,660 lb	8,464.034 kg

Conversion: 1 lb = 0.45359237 kg; displayed results are rounded. This multiplication excludes connection plates, bolts, weld metal, coatings, cutting allowances and actual material variation. Use the material takeoff for your own lengths and quantities.

Shape family context

What is a wide-flange shape?

A W-shape is a hot-rolled, doubly symmetric wide-flange section commonly used for beams and columns. Its relatively wide flanges and web distribute material efficiently for many bending and axial-force applications.

Learn how shape properties work

Common context

Common project roles include floor beams, roof beams, girders, columns, transfer members, and parts of braced or moment frames.

Detailing watch

Confirm orientation, camber, flange and web connection access, unbraced length assumptions, copes, stiffeners, and the exact grade and availability required by the project.

Portable reference files

Download W18X311 your way.

Every file is generated locally in your browser from the same nominal profile and AISC v16.0 reference record.

2D profile

CAD, vector, and image

Use the profile in CAD, illustration, plotting, reports, or presentations.

Properties & report

Tables and portable data

Take a printable datasheet, spreadsheet, structured record, or plain-text table.

Length-based 3D

Extrude a nominal member

Enter a member length in inches. Mesh files are generated from the nominal reference profile.

Member length in

One-click package

Complete 2D + data bundle

DXF, SVG, EPS, HPGL, PDF, PNG, WebP, CSV, XLSX, JSON, XML, YAML, TXT, and Markdown in one ZIP.

Choose a format. Files stay in your browser and are not uploaded.

Dimensions & properties

W18X311 reference data.

Values below are derived from the AISC Shapes Database v16.0 in US customary units. A dash indicates that a property is not applicable or not included for this family.

Nominal dimensions

W: 311 lb/ft
A: 91.6 in²
d: 22.3 in
ddet: 22.375 in
bf: 12 in
bfdet: 12 in
tw: 1.52 in
twdet: 1.5 in
tf: 2.74 in
tfdet: 2.75 in
kdes: 3.24 in
kdet: 3.563 in
k1: 1.563 in

Centroid & detailing

T: 15.125 in
WGi: 5.5 in

X-axis properties

Ix: 6,970 in⁴
Zx: 754 in³
Sx: 624 in³
rx: 8.72 in
rts: 3.53 in
ho: 19.6 in

Y- and z-axis properties

Iy: 795 in⁴
Zy: 207 in³
Sy: 132 in³
ry: 2.95 in

Torsion, warping & perimeters

J: 176 in⁴
Cw: 76,200 in⁶
PA: 76.7 in
PB: 88.7 in
PC: 56.6 in
PD: 68.6 in

Compare published reference values

W18X311 alongside nearby W records

These records share the same nominal series, outside envelope or leg arrangement, depending on the family. Peers are ordered by absolute weight difference, then listed depth and designation. The table does not rank structural performance or approve a substitution.

US customary values from the same AISC v16.0 dataset
Record	Weight (lb/ft)	Depth (in)	Area (in²)	Ix (in⁴)	Iy (in⁴)
W18X311 (this record)	311	22.3	91.6	6,970	795
W18X283	283	21.9	83.3	6,170	704
W18X258	258	21.5	76	5,510	628

Relative to W18X311, W18X283 changes nominal weight by -28 lb/ft, listed depth by -0.4 in, and area by -8.3 in². At the same hypothetical 20 ft length, the nominal weight difference is -560 lb.

Open these records in the full comparison tool

Compare the remaining dimensions, axis conventions, grade, availability and project requirements separately. Weight or section-property similarity does not establish matching connection geometry or member capacity.

Reference use only.

Data is derived from the AISC Shapes Database v16.0, consistent with the AISC Steel Construction Manual, 16th Edition, 1st Printing. AISC advises professional verification before use in a specific application. The downloadable DXF is a nominal reference profile and may simplify rolled fillets, flange tapers, angle radii, HSS corner radii, and other manufacturing geometry. Verify all dimensions and suitability before design, detailing, ordering, or fabrication.

From reference to deliverable

Need this steel modeled, detailed, and coordinated?

Start a conversation Detailing services