Profile Geometry
bbt

Square Hollow Sections (SHS)

SHS profiles are extremely popular in structural, mechanical, and architectural applications due to their flat surfaces (easy to weld/bolt) and excellent resistance to torsional loading. The uniform geometry provides equal strength along both major axes.

Design Characteristic
Iy = Iz, Wy = Wz

Dimensions & Structural Properties

DesignationMass (kg/m)Area (cm²)Iy (cm⁴)Wy (cm³)
40 x 40 x 3.03.334.249.464.73
50 x 50 x 4.05.456.9424.29.68
60 x 60 x 5.08.2310.552.717.6
80 x 80 x 5.011.114.213132.8
100 x 100 x 6.017.021.731763.4
150 x 150 x 8.034.343.71460195
Profile Geometry
hbt

Rectangular Hollow Sections (RHS)

RHS profiles offer flat surfaces for connections and are highly efficient when subjected to bending in one direction (the major axis). They are heavily used in trusses, bridges, and building frameworks.

Design Characteristic
Iy > Iz, Wy > Wz

Dimensions & Structural Properties

DesignationMass (kg/m)Area (cm²)Iy (cm⁴)Wy (cm³)
60 x 40 x 3.04.285.4426.18.71
80 x 40 x 4.06.718.5464.916.2
100 x 50 x 5.010.313.216132.3
120 x 60 x 6.015.119.334457.4
150 x 100 x 8.028.135.71090145
200 x 100 x 8.034.343.72150215
Profile Geometry
Dt

Circular Hollow Sections (CHS)

CHS (tubes/pipes) lack protruding corners, providing the best aerodynamic properties and aesthetic appeal. Because mass is uniformly distributed around the centroid, they offer the highest resistance to buckling and torsion of any cross-section.

Design Characteristic
I = (π/64)*(D⁴-d⁴)

Dimensions & Structural Properties

Designation (D x t)Mass (kg/m)Area (cm²)I (cm⁴)W (cm³)
42.4 x 3.23.093.947.453.51
60.3 x 4.05.557.0727.79.18
76.1 x 5.08.7711.269.718.3
114.3 x 6.016.020.429852.2
168.3 x 8.031.640.31300155
219.1 x 10.051.665.73650333
Cross Section Physics
Neutral AxisCentroid

Section Properties Guide

The structural performance of a profile is governed by its geometric properties. Area moment of inertia (I) predicts deflection under bending, while section modulus (W) predicts the maximum stress before yielding.

Design Characteristic
Stress (σ) = Moment (M) / Wy

Dimensions & Structural Properties

PropertySymbolUnitStructural Impact
Cross-sectional AreaAcm²Determines tensile and compressive strength. Affects mass.
Area Moment of InertiaI (Iy, Iz)cm⁴Measures stiffness against bending and deflection.
Elastic Section ModulusW (Wy, Wz)cm³Used to calculate yield stress limit during bending.
Radius of Gyrationr (ry, rz)cmCrucial for determining buckling resistance of columns.