What is the section modulus of MT6X5.9?

Sx = 1.61 inÃÂÃÂ³, Zx = 2.89 inÃÂÃÂ³ (strong axis). Sy = 0.354 inÃÂÃÂ³, Zy = 0.575 inÃÂÃÂ³ (weak axis).

What steel grade is standard for MT6X5.9?

ASTM A36 (Fy = 36 ksi) for MT-shapes. Verify with mill certificate.

What is the moment of inertia of MT6X5.9?

Ix = 6.61 inÃÂ¢ÃÂÃÂ´ about the strong axis and Iy = 0.543 inÃÂ¢ÃÂÃÂ´ about the weak axis. The radius of gyration is rx = 1.96 in and ry = 0.561 in.

MT6X5.9 Steel MT-shape — Section Properties

Dimensions

Property	Value	Unit
Depth (d)	6	152.4 mm
Flange Width (bf)	3.07	7.80 cm
Flange Thickness (tf)	0.225	5.7 mm
Web Thickness (tw)	0.177	4.5 mm
Area (A)	1.74 in²	11.2 cmÃÂÃÂ²
Weight	5.9 lb/ft	8.8 kg/m

Elastic Section Properties

Property	Strong Axis (X-X)	Weak Axis (Y-Y)	Unit
Moment of Inertia (I)	6.61	0.543	in⁴
Elastic Section Modulus (S)	1.61	0.354	in³
Plastic Section Modulus (Z)	2.89	0.575	in³
Radius of Gyration (r)	1.96	0.561	in

Torsional Properties

Property	Value	Unit
Torsional Constant (J)	0.025	in⁴
Warping Constant (Cw)	0.034	in⁶

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 = 6.61 in⁴, the strong-axis flexural stiffness is suitable for preliminary sizing of beams and beam-columns.

At 6" deep — one of the smallest standard sections available. Used for light-duty lintels, bracing, handrail posts, and miscellaneous structural iron.

Key Design Checks (AISC 360)

Check	Formula	This Section
Plastic moment	Mp = Zx × Fy	144.5 kip-in
Deflection	Δ = 5wLÃÂ¢ÃÂÃÂ´/(384EIx)	Use Ix = 6.61 in⁴
Torsion	St. Venant = GJ/L	J = 0.025 in⁴
Column buckling	KL/r ÃÂ¢ÃÂÃÂ Fcr	r_x = 1.96 in

Design Notes

Compactness: Verify flange and web slenderness against AISC 360 Table B4.1 classification limits for the governing load case (pure compression, pure flexure, or combined).
Combined loading: For members under simultaneous axial force and bending, use the interaction equations in AISC 360 Section H. The governing equation depends on the ratio of required to available axial strength.
Connection limit states: Check bolt bearing, tear-out, block shear, and weld strength at all connections. The governing connection limit state often controls the member size selection.

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

Section Properties Lookup — Compare with similar sections
Steel Beam Sizes Reference — Standard beam dimensions

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