Lead Square Tube Weight
Mass per metre and per foot for lead square tube at 11,340 kg/m³ (ASTM B29 (UNS L50049, chemical lead)). Every figure is for the section as drawn. A 6 m length of this size weighs 30.2 kg (67.7 lb per 20 ft).
At the reference dimensions (a = 40 mm, t = 3 mm) this section has a cross-sectional area of 444.0 mm², giving 5.035 kg/m (3.383 lb/ft). Against carbon steel's 7,850 kg/m³ that is +44.5 % — the same section in steel would be 3.485 kg/m.
Square Tube — formula and derivation
Area of a square tube
A = a² − (a − 2t)²
A = a² − (a − 2t)², which expands to A = 4t(a − t)
Worked through with the default dimensions:
A = a² − (a − 2t)²Inner side = 40 − 2 × 3 = 34.0 mmA = 40² − 34.0²A = 1600.0 − 1156.0A = 444.0 mm²
- a
- Side
- t
- Wall thickness
Weight follows from the area with no further geometry: m = A × 10⁻⁶ × ρ, where A is in mm², ρ in kg/m³ and m in kg/m. At 11,340 kg/m³ that is 5.0350 kg/m for the reference size above.
Lead square tube — size series
| Side | 1.5 | 2.0 | 3.0 | 4.0 | 5.0 | 6.0 |
|---|---|---|---|---|---|---|
| 15 mm | 0.919 kg/m · 0.617 lb/ft | 1.179 kg/m · 0.792 lb/ft | 1.633 kg/m · 1.097 lb/ft | 1.996 kg/m · 1.341 lb/ft | 2.268 kg/m · 1.524 lb/ft | 2.449 kg/m · 1.646 lb/ft |
| 20 mm | 1.259 kg/m · 0.846 lb/ft | 1.633 kg/m · 1.097 lb/ft | 2.313 kg/m · 1.555 lb/ft | 2.903 kg/m · 1.951 lb/ft | 3.402 kg/m · 2.286 lb/ft | 3.810 kg/m · 2.560 lb/ft |
| 25 mm | 1.599 kg/m · 1.074 lb/ft | 2.087 kg/m · 1.402 lb/ft | 2.994 kg/m · 2.012 lb/ft | 3.810 kg/m · 2.560 lb/ft | 4.536 kg/m · 3.048 lb/ft | 5.171 kg/m · 3.475 lb/ft |
| 30 mm | 1.939 kg/m · 1.303 lb/ft | 2.540 kg/m · 1.707 lb/ft | 3.674 kg/m · 2.469 lb/ft | 4.717 kg/m · 3.170 lb/ft | 5.670 kg/m · 3.810 lb/ft | 6.532 kg/m · 4.389 lb/ft |
| 40 mm | 2.620 kg/m · 1.760 lb/ft | 3.447 kg/m · 2.317 lb/ft | 5.035 kg/m · 3.383 lb/ft | 6.532 kg/m · 4.389 lb/ft | 7.938 kg/m · 5.334 lb/ft | 9.253 kg/m · 6.218 lb/ft |
| 50 mm | 3.300 kg/m · 2.217 lb/ft | 4.355 kg/m · 2.926 lb/ft | 6.396 kg/m · 4.298 lb/ft | 8.346 kg/m · 5.608 lb/ft | 10.206 kg/m · 6.858 lb/ft | 11.975 kg/m · 8.047 lb/ft |
| 60 mm | 3.980 kg/m · 2.675 lb/ft | 5.262 kg/m · 3.536 lb/ft | 7.757 kg/m · 5.212 lb/ft | 10.161 kg/m · 6.828 lb/ft | 12.474 kg/m · 8.382 lb/ft | 14.697 kg/m · 9.876 lb/ft |
| 80 mm | 5.341 kg/m · 3.589 lb/ft | 7.076 kg/m · 4.755 lb/ft | 10.478 kg/m · 7.041 lb/ft | 13.789 kg/m · 9.266 lb/ft | 17.010 kg/m · 11.430 lb/ft | 20.140 kg/m · 13.533 lb/ft |
| 100 mm | 6.702 kg/m · 4.503 lb/ft | 8.891 kg/m · 5.974 lb/ft | 13.200 kg/m · 8.870 lb/ft | 17.418 kg/m · 11.705 lb/ft | 21.546 kg/m · 14.478 lb/ft | 25.583 kg/m · 17.191 lb/ft |
Rows: side (mm). Columns: wall thickness (mm). Computed for Lead at 11340 kg/m³.
| Side | 1.5 | 2.0 | 3.0 | 4.0 | 5.0 | 6.0 |
|---|---|---|---|---|---|---|
| 15 mm | 81.0 | 104.0 | 144.0 | 176.0 | 200.0 | 216.0 |
| 20 mm | 111.0 | 144.0 | 204.0 | 256.0 | 300.0 | 336.0 |
| 25 mm | 141.0 | 184.0 | 264.0 | 336.0 | 400.0 | 456.0 |
| 30 mm | 171.0 | 224.0 | 324.0 | 416.0 | 500.0 | 576.0 |
| 40 mm | 231.0 | 304.0 | 444.0 | 576.0 | 700.0 | 816.0 |
| 50 mm | 291.0 | 384.0 | 564.0 | 736.0 | 900.0 | 1,056.0 |
| 60 mm | 351.0 | 464.0 | 684.0 | 896.0 | 1,100.0 | 1,296.0 |
| 80 mm | 471.0 | 624.0 | 924.0 | 1,216.0 | 1,500.0 | 1,776.0 |
| 100 mm | 591.0 | 784.0 | 1,164.0 | 1,536.0 | 1,900.0 | 2,256.0 |
Area is a property of the geometry alone, so this table is the same for every material. It is what you enter into a stress calculation; the mass table is what you enter into an order.
Each row is one nominal size. Because the area is computed from your dimensions rather than read from a mill table, a non-standard size is just as accurate — put it into the calculator above rather than interpolating between rows.
The same square tube in every material
Geometry is fixed and only density changes, so this table is the whole material-selection question in one view. Lead is highlighted. The percentage column is against carbon steel, which is the figure most quotations are built on.
| Material | Density kg/m³ | lb/in³ | Mass / length kg/m | lb/ft | vs carbon steel |
|---|---|---|---|---|---|
| Carbon Steel | 7,850 | 0.2836 | 3.485 | 2.342 | +0.0 % |
| Stainless Steel 304 | 8,000 | 0.2890 | 3.552 | 2.387 | +1.9 % |
| Stainless Steel 316 | 8,000 | 0.2890 | 3.552 | 2.387 | +1.9 % |
| Stainless Steel 316L | 8,000 | 0.2890 | 3.552 | 2.387 | +1.9 % |
| Stainless Steel 430 | 7,700 | 0.2782 | 3.419 | 2.297 | -1.9 % |
| Aluminum 6061-T6 | 2,700 | 0.0975 | 1.199 | 0.806 | -65.6 % |
| Aluminum 5052-H32 | 2,680 | 0.0968 | 1.190 | 0.800 | -65.9 % |
| Aluminum 7075-T6 | 2,810 | 0.1015 | 1.248 | 0.838 | -64.2 % |
| Copper C11000 | 8,940 | 0.3230 | 3.969 | 2.667 | +13.9 % |
| Brass C36000 | 8,500 | 0.3071 | 3.774 | 2.536 | +8.3 % |
| Bronze C93200 | 8,800 | 0.3179 | 3.907 | 2.626 | +12.1 % |
| Titanium Grade 2 | 4,510 | 0.1629 | 2.002 | 1.346 | -42.5 % |
| Gray Cast Iron | 7,200 | 0.2601 | 3.197 | 2.148 | -8.3 % |
| Lead | 11,340 | 0.4097 | 5.035 | 3.383 | +44.5 % |
| Rigid PVC (Type I) | 1,400 | 0.0506 | 0.622 | 0.418 | -82.2 % |
| HDPE (PE 100) | 960 | 0.0347 | 0.426 | 0.286 | -87.8 % |
Same geometry throughout, so the only variable is density. Carbon steel is highlighted as the baseline.
A note on using this table for costing: mass is not price. Aluminium is roughly a third of steel's mass here, but per kilogram it costs several times more, so a straight swap rarely saves money — what it buys is reduced load on a structure or a vehicle.
About lead
The densest material in the catalogue at 11,340 kg/m³ — 44 % heavier than carbon steel — and used precisely for that. Lead sheet is specified for acoustic and radiation shielding, where the performance metric is mass per unit area, so a sheet weight table is not an incidental output here, it is the design input: 1 mm of lead is about 11.34 kg/m². It is also extremely soft and creeps under sustained load, so it is normally supported, not self-carrying.
- Density
- 11,340 kg/m³ = 0.4097 lb/in³ · 1.4446× carbon steel · typical spread ±1 %
- Specification
- ASTM B29 (UNS L50049, chemical lead)
- Equivalents
- EN PB000 · GB Pb1
- Typical uses
- Radiation shielding · Acoustic and vibration isolation · Roof flashing and damp courses · Battery plates
Heavy-metal hazard: machining, welding and dross handling require controls. Creeps under its own weight at ambient temperature.
About square tube
Square tube expands cleanly to A = 4t(a − t), which makes the sensitivity obvious: for a given side, weight is almost exactly linear in wall thickness. Doubling a 2 mm wall to 4 mm adds about 1.9 times the mass, not twice, because the inner void shrinks as the wall grows. Its flat faces also make it the natural choice for welded frames and for anything that has to be drilled, tapped or bolted through a face — a round tube gives you only a tangent point where a square tube gives you a full flat.
Specified as side × wall thickness. Corner radii are standardised per EN 10219 and change the area slightly at heavier walls.
Download this data
Lead square tube — CSV
Both buttons below read the tables rendered on this page, so the file matches what you are looking at. The full catalogue — all 16 materials across all 10 sections — is on the downloads page.
Fields are quoted per RFC 4180, with a UTF-8 byte-order mark so Excel reads the mm² and · characters correctly. Blank lines separate the weight matrix from the area matrix.
Frequently asked questions
How much does lead square tube weigh?
At the reference dimensions (a = 40 mm, t = 3 mm) a lead square tube of this size weighs 5.035 kg/m, or 3.383 lb/ft. The table above lists the figure for every standard size so you can read your size directly instead of scaling.
How is the weight of square tube calculated?
Weight is cross-sectional area × length × density. For this shape the area is A = a² − (a − 2t)². At the reference dimensions that gives 444.0 mm², and multiplying by lead's density of 11,340 kg/m³ gives 5.035 kg/m. Nothing is looked up in a table — which is why a non-standard size is calculated just as accurately as a standard one.
Why does lead weigh more or less than steel?
It is heavier than carbon steel for the same section — about 44 % heavier at 11,340 kg/m³. Density is the only variable: the cross-sectional area depends purely on geometry, so a square tube of the same dimensions has the same area in every material and the mass simply scales with density. In this case the ratio is 1.4446× carbon steel.
What is the cross-sectional area of a square tube?
The area depends only on the dimensions, not on the material, so it is identical whichever material you select: at the reference dimensions it is 444.0 mm² (0.6882 in²). That is the number you would enter into a stress or deflection calculation, and it is why changing material on this page never changes the area column.
Does a lead square tube weigh the same as a lead part of a different shape?
No, and the difference is larger than most people expect. At equal nominal size, a square bar is 27.3 % heavier than a round bar, and a hollow section is typically 60–80 % lighter than the solid bar it replaces. Weight follows area, and area changes faster than dimensions do — which is exactly why this needs calculating rather than estimating.
Should I use Lead weight or carbon steel weight for costing?
Use the material you are actually buying. At 11,340 kg/m³ against carbon steel's 7,850 kg/m³, the same square tube differs by 44.5 % in mass. On a per-metre quote that is invisible; on a fabricated tonnage it is the difference between a margin and a loss. This page computes the steel figure as 3.485 kg/m for comparison.
Other materials, same square tube
The same geometry in every material, so the only variable is density.
- Carbon steel square tube — 7850 kg/m³
- SS 304 square tube — 8000 kg/m³
- SS 316 square tube — 8000 kg/m³
- AL 6061 square tube — 2700 kg/m³
- Copper square tube — 8940 kg/m³
- Brass square tube — 8500 kg/m³
- HDPE square tube — 960 kg/m³
- PVC square tube — 1400 kg/m³
Other Lead sections
The same density applied to every shape the site covers.
- Lead round bar — A = π/4 · d²
- Lead square bar — A = a²
- Lead hexagonal bar — A = (√3/2) · AF² ≈ 0.8660 · AF²
- Lead flat bar — A = w · t
- Lead plate — A = w · t
- Lead round tube — A = π/4 · (D² − d²), d = D − 2t
Reference data and tools
- Metal weight overview — how the calculation works
- All 16 materials — densities and specifications
- All 10 sections — formulas and size series
- Density chart — lightest to heaviest
- Metal weight calculator — any size, any material
- All calculators — metal weight and pipe weight
- Download the data — CSV, generated from the same source
- Cross-reference tables — DN / NPS / material equivalents
- Methodology and sources — where every number comes from
Square Tube area from A = a² − (a − 2t)². Mass computed as area × length × density at 11,340 kg/m³ (ASTM B29 (UNS L50049, chemical lead)). No weight on this page is copied from a published table — which is why figures can differ in the last significant digit from a mill's chart calculated at a nominal density.
- Elementary plane geometry. The circle, polygon and hollow-section area formulas.
- ASTM material specifications for each grade named in the material entry (A36, A240/A276, B209/B211/B221, B152/B16/B505, B265/B348, A48, B29, D1784, D3350).
- BIPM / NIST definitional constants: international inch = 25.4 mm, foot = 0.3048 m, pound = 0.45359237 kg.
Dataset version 2026.09.1 · dimensions last verified against source 2026-09-21. Found an error? Report it — corrections are issued with a version bump.