Below are the properties that are used in the calculations for each of our products.

Section Properties (parameters)

D = outside diameter (or length of long side) in inches
D’ = outside length (short side) in inches
t = wall thickness in inches
d = inside diameter (or inside length of long side) in inches (d = D- 2t)
d’ = Inside length (short side) in inches (d’ = D’- 2t)
Pi = Constant (3.14159)
WS = Weight/Foot of Steel (489.8 Lbs/Ft)

Calculation of Properties for Round Tube

Area (in2) = π/4 x (D 2 – d 2)
Moment of Inertia (in4)= π/64 x (D 4 – d 4)
Section Modulus(in4)= π/32 x [(D 4 – d 4) / D]
Radius of Gyration(in)= (Moment of Inertia / Area)1/2
Weight (lbs/ft ) = WS x Area / 144

Calculation of Properties for Square Tube

Area (in2) = (D 2 – d 2)
Moment of Inertia (in4) = (D 4 – d 4) / 12
Section Modulus(in4) = (D 4 – d 4) / 6D
Radius of Gyration (in) = (Moment of Inertia / Area)1/2
Weight (lbs/ft) = WS x Area / 144

Note: These section properties are calculated exclusive of the corner radii.

Calculation of Properties for Rectangular Tube 

Area (in2) = (DD’ – dd’)
Moment of Inertia major (in4)= (D 3 D’- d 3 d’) / 12
Section Modulus major (in4)= 2 x (Moment of Inertia major ) / D
Radius of Gyration major (in)= (Moment of Inertia major / Area)1/2
Weight (lbs/ft ) = WS x Area / 144

Note: These section properties are calculated with respect to the major axis only and are exclusive of the corner radii.

Calculation of Properties for Flat Sided Oval Tube

Area (in2)= 0.7854 (D’ 2 – d’ 2) + [(D – D’) (D’ – d’)]
Moment of Inertia major (in4) = 0.7854 (.25D 2) (.5D + 1.5D’) t
Section Modulus major (in4) = 2 x (Moment of Inertia major) / D
Radius of Gyration major (in) = (Moment of Inertia major / Area)1/2
Weight (lbs/ft ) = WS x Area / 144

Note: These section properties are calculated with respect to the major axis only.