US · W · W-shapes (wide flange)

W8x18 W200x26.6

W8x18 Wide-flange shape

  • ASTM A6/A6M
  • Design: AISC 360:2022
  • Unverified
Weight Surface area Equivalents XML
Mass26.65kg/m
A3,395mm²
Ix25.78010⁶ mm⁴
Zx249.410³ mm³
W8x18 cross-section
Cross-section drawn to scale from nominal dimensions. Cross-hair marks the centroid.

Dimensions

ParameterSymbolValueUnitUS customaryData
Depthd206.8mm8.140 inU
Flange widthbf133.4mm5.250 inU
Flange thicknesstf8.4mm0.330 inU
Web thicknesstw5.8mm0.230 inU
Root radiusr17.6mm0.300 inU

Section Properties

ParameterSymbolValueUnitUS customaryData
General
Mass per metre mass26.65kg/m17.91 lb/ftC
Gross area A3,395mm²5.26 in²C
About x-axis (major)
Second moment of area Ix Ix25.78010⁶ mm⁴61.9 in⁴C
Elastic section modulus Zx (min) Zx249.410³ mm³15.22 in³C
Plastic section modulus Sx Sx279.110³ mm³17.03 in³C
Radius of gyration rx rx87.1mm3.431 inC
About y-axis (minor)
Second moment of area Iy Iy3.31710⁶ mm⁴8.0 in⁴C
Elastic section modulus Zy (min) Zy49.710³ mm³3.04 in³C
Plastic section modulus Sy Sy76.410³ mm³4.66 in³C
Radius of gyration ry ry31.3mm1.231 inC
Torsion & warping
Torsion constant JApproximate thin-walled value, fillets neglected J0.06510⁶ mm⁴0.2 in⁴C
Warping constant IwIy·(d−tf)²/4 Iw32.6310⁹ mm⁶122 in⁶C
Surface area
External surface area extArea0.922m²/m3.025 ft²/ftC

Nominal designation mass 26.79 kg/m; calculated 26.65 kg/m (-0.5%).

Steel Grades

GradeStandard fy MPafu MPa NoteData
A992 (50 ksi) ASTM A992/A992M 345 450 Preferred grade for W-shapes (AISC) U

Strengths shown for governing thickness t = 8.4 mm. Density 7850 kg/m³, E = 200 000 MPa.

Where to buy

Producers of Hot-rolled beams & columns (I / H / W) – local mills first. Buy direct from the mill for large tonnages, or through a steel distributor / stockist for small quantities and cut lengths.

Nucor

United States · Charlotte, North Carolina

Local producer

Standards: ASTM A6, ASTM A992

Buying checklist
  • Specify the section designation, product standard and steel grade exactly (e.g. "W8x18 – ASTM A6/A6M – A992 (50 ksi)").
  • Ask for mill test certificates (EN 10204 type 3.1 or equivalent) traceable to the heat number.
  • Sections from another standard system are not automatically equivalent – have the engineer approve any substitution.
  • Check availability, minimum order quantity, stock lengths, lead time and delivery terms with the mill or distributor.

All producers of this product type →

Listing is informational only – not an endorsement, offer or confirmation of availability. Company details are marked UNVERIFIED until checked.

Source & Verification

Source publisher
Pending verification – nominal dimensions entered by the application developer
Source document
ASTM A6/A6M and AISC Shapes Database (W-shapes)
Edition
—
Publication year
—
Page reference
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Last updated
2026-10-12
Verification status
Unverified

Dimensions converted from the inch values of the AISC shapes database (d, bf, tw, tf, kdes; root radius = kdes − tf). Nominal weight 18 lb/ft. Verify against ASTM A6/A6M and the AISC Steel Construction Manual before design use.

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