Rectangular steel tubes (also known as rectangular hollow structural sections or rectangular HSS) sizes, dimensions and section properties are given in the following chart per Steel Construction Manual.

Rectangular steel tubes have an rectangular cross section except for rounded corners. Rectangular steel tubes are designated by "HSS", overall outside dimension (in.), and wall thickness. HSS10x8x5/8 is nominally 10 in. by 8 in. with a 5/8 in. wall thickness.

Moment of inertia, elastic section modulus, radius of gyration, torsional moment of inertia and plastic section modulus values are given by the following calculator for the selected rectangular steel tube size.


HSS Outside Dimension HSS Wall Thickness


Rectangular Steel Tube Sizes and Dimensions
Parameter Symbol Value Unit
Shape --- --- ---
Depth h --- in
Width b ---
Design wall thickness* tdes ---
Nominal weight w --- lb/ft
Area A --- in2
b/t --- --- ---
h/t --- --- ---
Second moment of area about X axis IX --- in4
Elastic section modulus about X axis SX --- in3
Radius of gyration about X axis rX --- in
Plastic section modulus about X axis ZX --- in3
Second moment of area about Y axis IY --- in4
Elastic section modulus about Y axis SY --- in3
Radius of gyration about Y axis rY --- in
Plastic section modulus about Y axis ZY --- in3
Workable flat depth hflat --- in
Workable flat width bflat ---
Polar moment of area J --- in4
Torsional constant for HSS shapes C --- in3
The total surface area of a square HSS section per feet Asurf --- ft2/ft

Note: Use dot "." as decimal separator.
Note *:The design wall thickness t, shall be used in calculations involving the wall thickness of hollow structural sections (HSS) per Steel Construction Manual Section B3.12.


Second Moment of Area: The capacity of a cross-section to resist bending.

Radius of Gyration (Area): The distance from an axis at which the area of a body may be assumed to be concentrated and the second moment area of this configuration equal to the second moment area of the actual body about the same axis.

Section Modulus: The moment of inertia of the area of the cross section of a structural member divided by the distance from the center of gravity to the farthest point of the section; a measure of the flexural strength of the beam.