Square Tube Weight Formula

The weight of a square tube depends on its outside dimension, wall thickness, and material density. This guide gives you a square tube weight chart in kg/m and lb/ft for common metric and inch sizes, the formula for calculating square tube weight per meter, and a worked example. As a quick reference, a 50 × 50 × 3 mm carbon steel tube weighs about 4.43 kg/m (2.98 lb/ft), and a 2 × 2 × 1/8 in tube weighs about 3.19 lb/ft. Use the chart to estimate weights before you request a quotation for square steel pipe.

Square Tube Weight Formula

You can estimate square steel tube weight, meaning the theoretical weight of a hollow square section, with this formula:

Weight (kg/m) ≈ [B² − (B − 2t)²] × 0.00785

Where:

• B = outside dimension of the square tube, in mm
• t = wall thickness, in mm
• 0.00785 = approximate coefficient based on carbon steel density of 7.85 g/cm³

The formula treats the tube as a perfect square ring with sharp corners. Real tubes have rounded corners, so the result can differ slightly from a standard theoretical weight table or from the weight you measure on a scale.

To find square tubing weight per foot, convert from kg/m:

Weight (lb/ft) = Weight (kg/m) × 0.672

In this article, “theoretical weight” means a value calculated from nominal size and wall thickness. “Actual weight” is what a scale reads, and it can differ because of tolerances, corner radius and coating.

If you want a simple square tube weight calculator, paste these formulas into a spreadsheet, with outside size in A2 and wall thickness in B2 (both in mm):

• kg/m: =(A2^2-(A2-2*B2)^2)*0.00785

• lb/ft: =(A2^2-(A2-2*B2)^2)*0.00785*0.672

Square Tube Weight Calculation Example

Calculate the weight of a 50 × 50 × 3 mm square tube.

1. Outside dimension: B = 50 mm
2. Wall thickness: t = 3 mm
3. Inner dimension: B − 2t = 50 − 6 = 44 mm
4. Outer area: 50² = 2,500
5. Inner area: 44² = 1,936
6. Difference: 2,500 − 1,936 = 564
7. Weight per meter: 564 × 0.00785 = 4.4274, rounded to 4.43 kg/m
8. Weight per foot: 4.4274 × 0.672 = 2.98 lb/ft

This matches the 50 × 50 × 3.0 row in the chart above, because the chart uses the same formula. A standard table that accounts for corner radii may show a slightly different value for the same size.

Read a full guide: Square Tube Weight Formula

Article source: https://article-realm.com/article/Business/85514-Square-Tube-Weight-Formula.html