M12.5X12.4 Steel Miscellaneous beam — Section Properties

Dimensions

Property Value Unit
Depth (d) 12.5 317.5 mm
Flange Width (bf) 3.75 9.53 cm
Flange Thickness (tf) 0.228 5.8 mm
Web Thickness (tw) 0.155 3.9 mm
Area (A) 3.63 in² 23.4 cm²
Weight 12.4 lb/ft 18.5 kg/m

Elastic Section Properties

Property Strong Axis (X-X) Weak Axis (Y-Y) Unit
Moment of Inertia (I) 89.3 2.01 in⁴
Elastic Section Modulus (S) 14.2 1.07 in³
Plastic Section Modulus (Z) 16.5 1.68 in³
Radius of Gyration (r) 4.96 0.744 in

Torsional Properties

Property Value Unit
Torsional Constant (J) 0.049 in⁴
Warping Constant (Cw) 76 in⁶
Distance Between Flange Centroids (ho) 12.3 in
Effective Radius (rts) 0.933 in

Section Profile Summary

This is a standard hot-rolled section profile covered by AISC 360. The tabulated section properties are computed from the nominal dimensions per the governing material standard. With Ix = 89.3 in⁴, the strong-axis flexural stiffness is suitable for preliminary sizing of beams and beam-columns.

At 12.5" deep and 12.4 lb/ft, this is a mid-range section suitable for floor beams, roof framing, and columns in low-to-mid-rise structures.

Key Design Checks (AISC 360)

Check Formula This Section
Plastic moment Mp = Zx × Fy 825 kip-in
Deflection Δ = 5wL⁴/(384EIx) Use Ix = 89.3 in⁴
Torsion St. Venant = GJ/L J = 0.049 in⁴
Column buckling KL/r → Fcr r_x = 4.96 in

Design Notes

Verification (AISC 360): All designs using this section must be verified by a licensed Professional Engineer. Before finalizing member selection, check beam-column interaction (P-M), lateral-torsional buckling, serviceability deflections, and all connection limit states. See Engineering Disclaimer.

Related Resources

Design Resources


Educational reference only. Verify all section properties against the current AISC 360 Manual and mill certificates before design. Results are PRELIMINARY — NOT FOR CONSTRUCTION.