S20×75 standard beam

Detailing dimensions and section properties from the AISC Shapes Database, 16th Edition. Values are shown to the nearest 1/16 in. as they appear on a shop drawing.

S20×75 measures 20 in. deep with a 6 3/8 in. flange, on a 5/8 in. web and 13/16 in. flanges.

At 75 lb per foot it is one of the 4 S20 sizes, which run from 66 to 96 lb/ft.

For strong-axis bending its section modulus is Sx = 128 in³ and its moment of inertia Ix = 1280 in⁴, with a plastic modulus Zx = 152 in³.

Detailing dimensions

Depth (d)20"
Flange width (bf)6 3/8"
Web thickness (tw)5/8"
Flange thickness (tf)13/16"
k (detailing)1 5/8"
Workable gage (g)3 1/2"

Section properties

Weight75 lb/ft
Area (A)22 in²
Ix1280 in⁴
Sx128 in³
Zx152 in³
rx7.62 in
Iy29.5 in⁴
Sy9.25 in³
Zy16.7 in³
ry1.16 in
J4.59 in⁴

Other S20 sizes

Same nominal size, different weight — useful when you are checking a substitution or a lighter section.

S20×66S20×86S20×96

Similar weight standard beams

Comparable 75 lb/ft sections in other standard beam sizes.

S18×7070 lb/ft · Sx 103 in³S24×8080 lb/ft · Sx 175 in³S24×9090 lb/ft · Sx 187 in³S18×54.754.7 lb/ft · Sx 89 in³S15×5050 lb/ft · Sx 64.7 in³S12×5050 lb/ft · Sx 50.6 in³S24×100100 lb/ft · Sx 199 in³S24×106106 lb/ft · Sx 240 in³

Detailing values are rounded to the nearest 1/16 in. per the AISC Steel Construction Manual. Verify critical dimensions against the current Manual before fabrication. Need S20×75 cut, formed, or fabricated? Huntington Steel & Supply Co.

Browse more: Standard beams · Steel Beam Size Chart

Interactive drawing