This free online calculator helps you quickly determine the section modulus (Z) of steel square and rectangular tubing, a key value in assessing bending resistance and structural performance. This tool supports both metric (mm³) and imperial (in³) units for seamless global use.
Rectangular Hollow Section Elastic Modulus Calculator
Moment of Inertia (Iyy): —cm⁴
Elastic Section Modulus (Sxx): —cm³
Elastic Section Modulus (Syy): —cm³
Plastic Section Modulus (Zxx): —cm³
Plastic Section Modulus (Zyy): —cm³
Cross-sectional Area (A): —cm²
Default values are for RHS 100×50×3.2mm: H = 100 mm, B = 50 mm, t = 3.2 mm.
What is the Elastic Section Modulus of a Rectangular Tube?
The elastic section modulus of a rectangular hollow section (rectangular tube) is a geometric property that measures the section’s resistance to bending. It is widely used in structural engineering and metal fabrication to calculate bending stresses.
Calculating the Section Modulus:
For a rectangular tube, the elastic section modulus about the strong axis is calculated as:
S = \frac{I}{c}
Where:
S = Elastic section modulus
I = Moment of inertia of the section
c = Distance from neutral axis to the outermost fiber
Moment of Inertia Formula:
The moment of inertia for a rectangular tube is calculated by subtracting the inner hollow part from the outer rectangle:
I = \frac{b \cdot h^3 - b_i \cdot h_i^3}{12}
Where:
b = Outer width
h = Outer height
bi = Inner width
hi = Inner height
Application:
The elastic section modulus is used in bending stress calculation via:
σ = \frac{M}{S}
Where:
σ = Maximum bending stress
M = Applied bending moment
S = Section modulus (mm³ or in³)
Use this calculator to accurately determine the bending strength of steel rectangular tubes, with support for both metric and imperial units.
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✅ Key Features
- 💡 Calculates section modulus (Z) for rectangular steel tubes
- 📏 Supports both metric and imperial units
- ⚙️ Suitable for SHS (Rectangular Hollow Sections)
- 🔧 Ideal for structural design, beam analysis, and profile bending projects
- ⚡ Instant output with no signup required
✅ How to Use
- Select your preferred unit: mm / inch
- Input outer width and wall thickness of the rectangular tube
- Click “Calculate” to get the section modulus (Z) instantly
✅ Frequently Asked Questions (FAQ)
- Q1: What is the section modulus used for? A: It’s a structural measure that shows a beam or profile’s resistance to bending.
- Q2: Does this calculator work for rectangular tubes? A: Sure. This version is for Square and rectangular tubes.
- Q3: Can I use this calculator for aluminum rectangular tubing? A: Yes. The section modulus formula applies to all materials with the same cross-section shape.
- Q4: Do I need to convert units manually? A: No. Just choose mm or inch before entering your values, and the calculator handles the rest.