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Structuralaka: wide-flange sectionaka: W-sectionaka: H-pile

W-Shape

In Plain English

A standard wide-flange steel section identified by its depth and weight, such as W12×50.

Definition

The designation for wide-flange structural steel sections as defined by the American Institute of Steel Construction (AISC). W-shapes are identified by their nominal depth and weight per linear foot, such as W18×35 (18-inch nominal depth, 35 lb/ft). Their wide flanges provide greater bending capacity and connection area than older S-shape (American Standard) sections.

Why It Matters in Bidding

W-shapes are the workhorse of structural steel bids, and their weight per foot directly drives the tonnage that fabricators and erectors price. Estimators read the W-designation to calculate total steel weight, since fabricated steel is bid largely by the pound plus connection complexity. Accurate beam and column takeoffs from the framing plans are the foundation of a competitive steel number.

Example

Taking off a framing plan, the steel estimator multiplies each W18×35 beam's length by 35 pounds per foot, sums the tonnage by member type, and sends the package to fabricators for unit pricing on material and shop connections.

Related Terms

I-BeamStructural SteelBeamGirder

Frequently Asked Questions

Read the weight per foot from the W-designation (the number after the depth, such as 35 in W18×35), multiply by each member's length, and sum across all beams and columns. Convert pounds to tons for fabricator pricing, then add an allowance for connections, plates, bolts, and waste, which are not in the bare shape weight.
W-shapes have wider, parallel flanges that give greater bending capacity and more area for bolted or welded connections per pound of steel, making them more efficient and easier to detail. They dominate modern framing, so most takeoffs and fabricator pricing assume W-shapes unless the drawings specifically call out older S-shape sections.
Bare W-shape weight is only the starting point. Estimators add connection material, plates, stiffeners, bolts and welds, shop and field labor, coatings or fireproofing, anchor rods, shipping, and erection crane time. Connection complexity and erection sequencing often influence the final price more than the raw tonnage alone.

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