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Hollow Section Weight Calculator

Rectangular / Square (RHS/SHS) Circular (CHS / Pipe)

Steel: 7850, Aluminum: 2700, Stainless Steel: 8000

Calculation Results

Weight per Meter: 0 kg/m

Total Weight: 0 kg

function toggleInputs() { var shape = document.getElementById("sectionShape").value; var heightContainer = document.getElementById("heightContainer"); var widthLabel = document.getElementById("widthLabel"); if (shape === "circular") { heightContainer.style.display = "none"; widthLabel.innerText = "Outside Diameter (mm)"; } else { heightContainer.style.display = "block"; widthLabel.innerText = "Width (mm)"; } } function calculateHollowWeight() { var shape = document.getElementById("sectionShape").value; var w = parseFloat(document.getElementById("dimWidth").value); var h = parseFloat(document.getElementById("dimHeight").value); var t = parseFloat(document.getElementById("thickness").value); var l = parseFloat(document.getElementById("length").value); var density = parseFloat(document.getElementById("density").value); var resultDiv = document.getElementById("weightResult"); if (isNaN(w) || isNaN(t) || isNaN(l) || isNaN(density) || (shape === "rectangular" && isNaN(h))) { alert("Please enter valid numeric values for all fields."); return; } var crossSectionalArea = 0; // in mm2 if (shape === "rectangular") { // Area = Outer Area – Inner Area var outerArea = w * h; var innerArea = (w – 2 * t) * (h – 2 * t); crossSectionalArea = outerArea – innerArea; } else { // Circular: Area = PI * (R^2 – r^2) var outerRadius = w / 2; var innerRadius = outerRadius – t; crossSectionalArea = Math.PI * (Math.pow(outerRadius, 2) – Math.pow(innerRadius, 2)); } // Volume per meter in m3 = (Area in mm2 / 1,000,000) * 1m var volumePerMeter = crossSectionalArea / 1000000; var wPerM = volumePerMeter * density; var totalW = wPerM * l; document.getElementById("weightPerMeter").innerText = wPerM.toFixed(3); document.getElementById("totalWeight").innerText = totalW.toFixed(2); resultDiv.style.display = "block"; }

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Understanding Hollow Section Weights

Hollow sections are vital components in structural engineering, architecture, and mechanical manufacturing. Whether you are working with Square Hollow Sections (SHS), Rectangular Hollow Sections (RHS), or Circular Hollow Sections (CHS), knowing the exact weight is crucial for logistics, structural load calculations, and cost estimation.

How Hollow Section Weight is Calculated

The weight of a hollow section is determined by its cross-sectional area, the length of the member, and the density of the material (usually carbon steel). The fundamental formula is:

Weight = [Outer Volume – Inner Volume] × Density

1. Square and Rectangular Sections (SHS/RHS)

For rectangular sections, we calculate the area of the outer rectangle and subtract the area of the inner void created by the wall thickness.
Formula: Area = (Width × Height) - ((Width - 2t) × (Height - 2t))

2. Circular Hollow Sections (CHS)

For pipes and tubes, we use the area of a circle formula.
Formula: Area = π × (R² - r²) where R is the outer radius and r is the inner radius.

Common Material Densities

• Mild Steel: 7,850 kg/m³ (Standard for most structural RHS/SHS)
• Aluminum: 2,700 kg/m³
• Stainless Steel: 7,900 – 8,000 kg/m³
• Copper: 8,960 kg/m³

Example Calculation

Suppose you have a 100mm x 100mm SHS with a 5mm wall thickness and a length of 6 meters.

1. Outer Area = 100 * 100 = 10,000 mm²
2. Inner Width = 100 – (2 * 5) = 90mm
3. Inner Area = 90 * 90 = 8,100 mm²
4. Steel Area = 10,000 – 8,100 = 1,900 mm² (0.0019 m²)
5. Weight per Meter = 0.0019 m² × 7,850 kg/m³ = 14.915 kg/m
6. Total Weight for 6m = 14.915 * 6 = 89.49 kg

Why Use This Calculator?

Manual calculations are prone to human error, especially when converting units from millimeters to meters or calculating circular volumes. This tool provides an instant, accurate result for engineers, fabricators, and students. It helps in:

• Estimating shipping and freight costs.
• Ensuring cranes and lifting equipment are within safety limits.
• Calculating the total load on a building's foundation.
• Quoting projects accurately based on material weight.