Rigid PVC (Type I) Square Tube Weight
Mass per metre and per foot for rigid pvc (type i) square tube at 1,400 kg/m³ (ASTM D1784 Cell Classification 12454). Every figure is for the section as drawn. A 6 m length of this size weighs 3.7 kg (8.4 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 0.622 kg/m (0.418 lb/ft). Against carbon steel's 7,850 kg/m³ that is -82.2 % — 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 1,400 kg/m³ that is 0.6216 kg/m for the reference size above.
PVC square tube — size series
| Side | 1.5 | 2.0 | 3.0 | 4.0 | 5.0 | 6.0 |
|---|---|---|---|---|---|---|
| 15 mm | 0.113 kg/m · 0.076 lb/ft | 0.146 kg/m · 0.098 lb/ft | 0.202 kg/m · 0.135 lb/ft | 0.246 kg/m · 0.166 lb/ft | 0.280 kg/m · 0.188 lb/ft | 0.302 kg/m · 0.203 lb/ft |
| 20 mm | 0.155 kg/m · 0.104 lb/ft | 0.202 kg/m · 0.135 lb/ft | 0.286 kg/m · 0.192 lb/ft | 0.358 kg/m · 0.241 lb/ft | 0.420 kg/m · 0.282 lb/ft | 0.470 kg/m · 0.316 lb/ft |
| 25 mm | 0.197 kg/m · 0.133 lb/ft | 0.258 kg/m · 0.173 lb/ft | 0.370 kg/m · 0.248 lb/ft | 0.470 kg/m · 0.316 lb/ft | 0.560 kg/m · 0.376 lb/ft | 0.638 kg/m · 0.429 lb/ft |
| 30 mm | 0.239 kg/m · 0.161 lb/ft | 0.314 kg/m · 0.211 lb/ft | 0.454 kg/m · 0.305 lb/ft | 0.582 kg/m · 0.391 lb/ft | 0.700 kg/m · 0.470 lb/ft | 0.806 kg/m · 0.542 lb/ft |
| 40 mm | 0.323 kg/m · 0.217 lb/ft | 0.426 kg/m · 0.286 lb/ft | 0.622 kg/m · 0.418 lb/ft | 0.806 kg/m · 0.542 lb/ft | 0.980 kg/m · 0.659 lb/ft | 1.142 kg/m · 0.768 lb/ft |
| 50 mm | 0.407 kg/m · 0.274 lb/ft | 0.538 kg/m · 0.361 lb/ft | 0.790 kg/m · 0.531 lb/ft | 1.030 kg/m · 0.692 lb/ft | 1.260 kg/m · 0.847 lb/ft | 1.478 kg/m · 0.993 lb/ft |
| 60 mm | 0.491 kg/m · 0.330 lb/ft | 0.650 kg/m · 0.437 lb/ft | 0.958 kg/m · 0.643 lb/ft | 1.254 kg/m · 0.843 lb/ft | 1.540 kg/m · 1.035 lb/ft | 1.814 kg/m · 1.219 lb/ft |
| 80 mm | 0.659 kg/m · 0.443 lb/ft | 0.874 kg/m · 0.587 lb/ft | 1.294 kg/m · 0.869 lb/ft | 1.702 kg/m · 1.144 lb/ft | 2.100 kg/m · 1.411 lb/ft | 2.486 kg/m · 1.671 lb/ft |
| 100 mm | 0.827 kg/m · 0.556 lb/ft | 1.098 kg/m · 0.738 lb/ft | 1.630 kg/m · 1.095 lb/ft | 2.150 kg/m · 1.445 lb/ft | 2.660 kg/m · 1.787 lb/ft | 3.158 kg/m · 2.122 lb/ft |
Rows: side (mm). Columns: wall thickness (mm). Computed for Rigid PVC (Type I) at 1400 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. Rigid PVC (Type I) 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 rigid pvc (type i)
Unplasticised polyvinyl chloride, the standard solvent-welded pipe and duct material. At 1,400 kg/m³ it is 82 % lighter than carbon steel — the single biggest mass saving available in the catalogue — which is why PVC pipe is specified for drainage, irrigation and fume ducting where nothing structural is asked of it. The figure assumes rigid, unplasticised compound; flexible PVC contains plasticiser and runs 1,200–1,500 kg/m³, and foamed PVC is far lower again.
- Density
- 1,400 kg/m³ = 0.0506 lb/in³ · 0.1783× carbon steel · typical spread ±3 %
- Specification
- ASTM D1784 Cell Classification 12454
- Equivalents
- EN PVC-U · JIS PVC · GB PVC-U
- Typical uses
- Drainage and soil pipe · Irrigation and fume duct · Chemical process pipework · Electrical conduit
Density is formulation-dependent: rigid compound 1,380–1,450 kg/m³, plasticised grades are lighter and foamed grades much lighter. Strength falls sharply above about 60 °C.
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
PVC 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 rigid pvc (type i) square tube weigh?
At the reference dimensions (a = 40 mm, t = 3 mm) a rigid pvc (type i) square tube of this size weighs 0.622 kg/m, or 0.418 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 rigid pvc (type i)'s density of 1,400 kg/m³ gives 0.622 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 rigid pvc (type i) weigh more or less than steel?
It is lighter than carbon steel for the same section — about 82 % lighter at 1,400 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 0.1783× 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 pvc square tube weigh the same as a pvc 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 PVC weight or carbon steel weight for costing?
Use the material you are actually buying. At 1,400 kg/m³ against carbon steel's 7,850 kg/m³, the same square tube differs by 82.2 % 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
- AL 5052 square tube — 2680 kg/m³
Other PVC sections
The same density applied to every shape the site covers.
- PVC round bar — A = π/4 · d²
- PVC square bar — A = a²
- PVC hexagonal bar — A = (√3/2) · AF² ≈ 0.8660 · AF²
- PVC flat bar — A = w · t
- PVC plate — A = w · t
- PVC 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 1,400 kg/m³ (ASTM D1784 Cell Classification 12454). 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.