Complete Guide to Carbon Steel Square Tube Weight and Hollow Section Calculation
Complete Guide to Carbon Steel Square Tube Weight and Hollow Section Calculation
Carbon steel square pipe,carbon steel rectangular tube and round steel pipe are essential components in contemporary steel structure projects.They are widely used in construction, machinery, bridges, and transport systems because of their superior strength, consistent dimensions, and excellent weldability.
For engineers, buyers, and importers,a clear understanding of carbon steel square tube weight and the method of calculating square hollow section weight is critical.It ia important for them to plan costs,determine design loads, and eatimate shipment tonnage.
1. Theoretical and Actual Weight Calculation
For carbon steel pipes, two types of weight calculations are commonly used worldwide:
Theoretical weight – based on standard formulas and steel density.
Actual weight – measured after production, including galvanizing or coating layers.
The following formulas are widely accepted by international China pipe manufacturers:
1.1 For Round Tubes (including galvanized round steel tubing):
Weight (kg/m) = (O.D. - w.t) × w.t × 0.0246615
This calculation applies to plain carbon steel and hot galvanized steel round pipe. To incorporate the zinc coating, the result is multiplied by an adjustment factor of ×1.03.
1.2 For Square Tubes and Rectangular Tubes:
Weight (kg/m) = [ (side1 + side2) × 2 / 3.14 – w.t ] × w.t × 0.0246615
This is the standard theoretical formula for carbon steel square and rectangular tube weight.
Each country has slight variations depending on standards such as GB/T 6728, EN 10219, or ASTM A500.
For galvanized steel hollow sections, the calculated weight should be multiplied by 1.03 to account for the additional zinc coating.
1.3 For More Accurate Project or Packing Calculations:
Weight (kg/m) = [ ((side1 + side2) × 2 - 5) / 3.14 – w.t ] × w.t × 0.0246615
This practical version provides a closer approximation to the actual square tube steel weight after surface treatment and is often used for export documentation.
2. The Evolution of Weight Calculation Standards
Previously, numerous factories depended on manual reference charts for square hollow sections, frequently resulting in deviations of up to 3%.
Today, advanced square tube manufacturers use digital modeling and automated weighing systems. These advancements enable accurate forecasting of square tube carbon steel mass, guaranteeing alignment between theoretical calculations and real-world outcomes.
Different national standards affect weight slightly:
GB/T 6728 (China): nominal wall thickness
EN 10219 (Europe): average wall thickness
ASTM A500 (USA): minimum wall thickness
These distinctions clarify why the load-bearing capacity of square tubes can vary, even for tubes with comparable dimensions.
3. Factors That Influence the Final Weight
Even with accurate calculations, minor variations can arise:
Galvanizing or coating increases 3–7% to carbon steel square tube weight.
Manufacturing tolerance in cold forming may result in a ±0.5mm variation in wall thickness.
Moisture, oil film, or surface residue may also change the total steel hollow section weight.
For international shipping, the acceptable variation between theoretical and actual weight is generally within ±5%.
4. Standard Carbon Steel Square Tube & Rectangular Tube Weight Table
As a professional square tube manufacturer from Tianjin, China, we provide precise steel hollow section weight data, customized cutting service, and full documentation to ensure quality and consistency in every shipment.
