S12x50 Section Properties — American Standard Beam

S12x50 Section Properties

Complete geometric properties for the S12x50 (American Standard Beam) per AISC Steel Construction Manual, 16th Edition. This section weighs 50.0 lb/ft. American Standard beams (S-shapes) have an I-shaped cross section with sloped inner flange surfaces. They are one of the original structural steel shapes and are still used in certain applications.

Property Value Unit
Depth 12 in
Flange Width 5.477 in
Flange Thickness 0.659 in
Web Thickness 0.687 in
Cross-Sectional Area 14.7 in²
Moment of Inertia (x-axis) 305 in⁴
Moment of Inertia (y-axis) 15.7 in⁴
Elastic Section Modulus (x-axis) 50.8 in³
Elastic Section Modulus (y-axis) 5.74 in³
Plastic Section Modulus (x-axis) 58.8 in³
Plastic Section Modulus (y-axis) 9.15 in³
Radius of Gyration (x-axis) 4.55 in
Radius of Gyration (y-axis) 1.03 in
Torsional Constant 1.73 in⁴

About American Standard Beam Shapes

American Standard beams (S-shapes) have an I-shaped cross section with sloped inner flange surfaces. They are one of the original structural steel shapes and are still used in certain applications.

How to Use This Data

The properties listed above are used in structural engineering calculations including:

  • Moment of Inertia (I) — used to calculate deflection and stiffness. Higher I = less deflection under load.
  • Section Modulus (S) — used to calculate bending stress. σ = M/S, where M is the bending moment.
  • Plastic Section Modulus (Z) — used in LRFD design to calculate plastic moment capacity. Mp = Fy × Z.
  • Radius of Gyration (r) — used in column buckling calculations. Higher r = more resistance to buckling.
  • Torsional Constant (J) — used to calculate torsional resistance and lateral-torsional buckling.
  • Area (A) — used to calculate axial capacity and self-weight.

Use our interactive Section Properties Calculator to compare shapes, calculate composite sections, or look up any AISC shape. For beam design, try our Beam Calculator or Wood Beam Designer.


Data source: AISC Steel Construction Manual, 16th Edition. All dimensions in inches, areas in square inches, moments of inertia in in⁴, section moduli in in³. Values are for design reference — always verify against the current edition of the AISC Manual for final design.

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