Rectangular Hollow Tube Weight Calculator

How it works is simple. A rectangular hollow tube weight calculator finds the mass of a hollow metal tube. It uses tube outer size, wall thickness, length, and material density. It then subtracts the hollow part from the solid part.

The tool gives mass in kilograms or weight in newtons. You can use it for beams, frames, or a quick shop check.

Why calculate the weight of a rectangular hollow tube?

Why you check weight? Because you plan, lift, or buy. For example, an engineer is teaching a team. He shows a tube to a student. The team needs to know how much one 3 m tube will weigh. They must handle it safely. They must budget for transport. So you use the calculator to get a clear number fast.

Calculate: step by step example

First know the formula.
Cross sectional area = outer area − inner area.
Outer area = outer width × outer height.
Inner width = outer width − 2 × thickness.
Inner height = outer height − 2 × thickness.
Volume = cross area × length.
Mass = volume × density.
Weight (N) = mass × 9.81.

Now plug real numbers. The teacher uses metric and speaks in class.

1. Given: outer width = 100 mm, outer height = 50 mm. Convert to meters.
   100 mm = 0.100 m.
   50 mm = 0.050 m.
2. Wall thickness = 5 mm = 0.005 m. Length = 3 m. Density (steel) = 7850 kg/m³.
3. Outer area = 0.100 × 0.050 = 0.00500 m².
4. Inner width = 0.100 − 2×0.005 = 0.100 − 0.010 = 0.090 m.
   Inner height = 0.050 − 0.010 = 0.040 m.
5. Inner area = 0.090 × 0.040 = 0.00360 m².
6. Cross sectional area = 0.00500 − 0.00360 = 0.00140 m².
7. Volume = 0.00140 × 3 = 0.00420 m³.
8. Mass = 0.00420 × 7850. Do digit math:
   7850 × 0.00420 = 7850 × 42 / 10000.
   7850 × 42 = 7850 × 40 + 7850 × 2 = 314000 + 15700 = 329700.
   329700 / 10000 = 32.970 kg.
9. Weight (force) = 32.970 × 9.81 ≈ 323.4 N.

So the tube mass is about 32.97 kg. The teacher notes this in front of the learner. They check the number and nod.

FAQs

Q: What units do I use?

A: Use meters for length and kg/m³ for density. Convert mm to m first.

Q: Can I use another material?

A: Yes. Replace density with the material value and repeat the steps.

Q: Do I always get mass or weight?

A: The calculator can show both. Mass in kg. Weight in newtons if you multiply by 9.81.

Final Words

You can do this by hand for a quick check. Yet the calculator saves time and cuts error. Use it to plan lifts and costs.