Common context
Common project roles include floor beams, roof beams, girders, columns, transfer members, and parts of braced or moment frames.
AISC v16.0 · W shape
W21X166
W21X166 weighs 166 lb/ft, has a depth of 22.5 in, a cross-sectional area of 48.8 in², and an x-axis elastic section modulus Sx of 380 in³. Open the full US customary property record or generate 2D, data, report, and 3D reference files locally in your browser.
Nominal profile
Units · inches
Building nominal profile…
- Weight
- 166 lb/ft
- Area
- 48.8 in²
- Depth
- 22.5 in
- Elastic Sx
- 380 in³
From designation to geometry
Reading the W21X166 record
The 21 in depth series in W21X166 is a designation. The tabulated depth d is 22.5 in and flange width bf is 12.4 in. The separately listed detailing depth ddet is 22.5 in.
The web thickness tw is 0.75 in and flange thickness tf is 1.36 in. Keep the exact designation with these dimensions: matching the depth series does not guarantee matching flanges, web geometry or connection fit.
Ix = 4,280 in⁴ and Iy = 435 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 W21X166
Assume 3 pieces, each 20 ft (6.096 m) long. This is a hypothetical quantity example, not a stock-length or lifting recommendation.
| Quantity | Calculation | Nominal pounds | Kilogram equivalent |
|---|---|---|---|
| One 20 ft piece | 20 ft × 166 lb/ft | 3,320 lb | 1,505.927 kg |
| 3 pieces | 3 × 3,320 lb | 9,960 lb | 4,517.78 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 workDetailing 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 W21X166 your way.
Every file is generated locally in your browser from the same nominal profile and AISC v16.0 reference record.
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Tables and portable data
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Enter a member length in inches. Mesh files are generated from the nominal reference profile.
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Dimensions & properties
W21X166 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 Nominal weight
- 166 lb/ft
- A Area
- 48.8 in²
- d Depth / angle leg dimension d
- 22.5 in
- ddet Detailing depth
- 22.5 in
- bf Flange width
- 12.4 in
- bfdet Detailing flange width
- 12.375 in
- tw Web thickness
- 0.75 in
- twdet Detailing web thickness
- 0.75 in
- tf Flange thickness
- 1.36 in
- tfdet Detailing flange thickness
- 1.375 in
- kdes Design k distance
- 1.86 in
- kdet Detailing k distance
- 2.625 in
- k1 Web-toe k distance
- 1.563 in
Centroid & detailing
- T Detailing T distance
- 17.25 in
- WGi Workable gage, inner
- 5.5 in
X-axis properties
- Ix X-axis moment of inertia
- 4,280 in⁴
- Zx X-axis plastic section modulus
- 432 in³
- Sx X-axis elastic section modulus
- 380 in³
- rx X-axis radius of gyration
- 9.36 in
- rts Effective radius of gyration
- 3.48 in
- ho Flange centroid distance
- 21.1 in
Y- and z-axis properties
- Iy Y-axis moment of inertia
- 435 in⁴
- Zy Y-axis plastic section modulus
- 108 in³
- Sy Y-axis elastic section modulus
- 70 in³
- ry Y-axis radius of gyration
- 2.99 in
Torsion, warping & perimeters
- J Torsional constant
- 23.6 in⁴
- Cw Warping constant
- 48,500 in⁶
- PA Shape perimeter PA
- 79.8 in
- PB Shape perimeter PB
- 92.2 in
- PC Shape perimeter PC
- 57.4 in
- PD Shape perimeter PD
- 69.8 in
Compare published reference values
W21X166 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.
| Record | Weight (lb/ft) | Depth (in) | Area (in²) | Ix (in⁴) | Iy (in⁴) |
|---|---|---|---|---|---|
| W21X166 (this record) | 166 | 22.5 | 48.8 | 4,280 | 435 |
| W21X182 | 182 | 22.7 | 53.6 | 4,730 | 483 |
| W21X147 | 147 | 22.1 | 43.2 | 3,630 | 376 |
Relative to W21X166, W21X182 changes nominal weight by +16 lb/ft, listed depth by +0.2 in, and area by +4.8 in². At the same hypothetical 20 ft length, the nominal weight difference is +320 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.
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