Stainless Steel 430 Square Tube Weight
Mass per metre and per foot for stainless steel 430 square tube at 7,700 kg/m³ (ASTM A240 (UNS S43000)). Every figure is for the section as drawn. A 6 m length of this size weighs 20.5 kg (45.9 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 3.419 kg/m (2.297 lb/ft). Against carbon steel's 7,850 kg/m³ that is -1.9 % — 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 7,700 kg/m³ that is 3.4188 kg/m for the reference size above.
SS 430 square tube — size series
| Side | 1.5 | 2.0 | 3.0 | 4.0 | 5.0 | 6.0 |
|---|---|---|---|---|---|---|
| 15 mm | 0.624 kg/m · 0.419 lb/ft | 0.801 kg/m · 0.538 lb/ft | 1.109 kg/m · 0.745 lb/ft | 1.355 kg/m · 0.911 lb/ft | 1.540 kg/m · 1.035 lb/ft | 1.663 kg/m · 1.118 lb/ft |
| 20 mm | 0.855 kg/m · 0.574 lb/ft | 1.109 kg/m · 0.745 lb/ft | 1.571 kg/m · 1.056 lb/ft | 1.971 kg/m · 1.325 lb/ft | 2.310 kg/m · 1.552 lb/ft | 2.587 kg/m · 1.739 lb/ft |
| 25 mm | 1.086 kg/m · 0.730 lb/ft | 1.417 kg/m · 0.952 lb/ft | 2.033 kg/m · 1.366 lb/ft | 2.587 kg/m · 1.739 lb/ft | 3.080 kg/m · 2.070 lb/ft | 3.511 kg/m · 2.359 lb/ft |
| 30 mm | 1.317 kg/m · 0.885 lb/ft | 1.725 kg/m · 1.159 lb/ft | 2.495 kg/m · 1.676 lb/ft | 3.203 kg/m · 2.152 lb/ft | 3.850 kg/m · 2.587 lb/ft | 4.435 kg/m · 2.980 lb/ft |
| 40 mm | 1.779 kg/m · 1.195 lb/ft | 2.341 kg/m · 1.573 lb/ft | 3.419 kg/m · 2.297 lb/ft | 4.435 kg/m · 2.980 lb/ft | 5.390 kg/m · 3.622 lb/ft | 6.283 kg/m · 4.222 lb/ft |
| 50 mm | 2.241 kg/m · 1.506 lb/ft | 2.957 kg/m · 1.987 lb/ft | 4.343 kg/m · 2.918 lb/ft | 5.667 kg/m · 3.808 lb/ft | 6.930 kg/m · 4.657 lb/ft | 8.131 kg/m · 5.464 lb/ft |
| 60 mm | 2.703 kg/m · 1.816 lb/ft | 3.573 kg/m · 2.401 lb/ft | 5.267 kg/m · 3.539 lb/ft | 6.899 kg/m · 4.636 lb/ft | 8.470 kg/m · 5.692 lb/ft | 9.979 kg/m · 6.706 lb/ft |
| 80 mm | 3.627 kg/m · 2.437 lb/ft | 4.805 kg/m · 3.229 lb/ft | 7.115 kg/m · 4.781 lb/ft | 9.363 kg/m · 6.292 lb/ft | 11.550 kg/m · 7.761 lb/ft | 13.675 kg/m · 9.189 lb/ft |
| 100 mm | 4.551 kg/m · 3.058 lb/ft | 6.037 kg/m · 4.057 lb/ft | 8.963 kg/m · 6.023 lb/ft | 11.827 kg/m · 7.948 lb/ft | 14.630 kg/m · 9.831 lb/ft | 17.371 kg/m · 11.673 lb/ft |
Rows: side (mm). Columns: wall thickness (mm). Computed for Stainless Steel 430 at 7700 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. Stainless Steel 430 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 stainless steel 430
A ferritic straight-chromium grade — 17 % Cr, essentially no nickel — and therefore magnetic. Its 7,700 kg/m³ makes it the lightest of the stainless family here, a 1.9 % saving against 304 and the only stainless that undercuts carbon steel on mass. That, plus a nickel-free price, is why it dominates appliance trim, kitchen splashbacks and interior decorative panels where corrosion demand is mild and a magnet will be used on it anyway.
- Density
- 7,700 kg/m³ = 0.2782 lb/in³ · 0.9809× carbon steel · typical spread ±1 %
- Specification
- ASTM A240 (UNS S43000)
- Equivalents
- EN 1.4016 · JIS SUS430 · GB 10Cr17
- Typical uses
- Appliance and kitchen panels · Interior decorative trim · Automotive exhaust trim · Elevator cladding
Ferritic grades have lower ductility and weldability than 304; avoid specifying it for formed or welded structural work.
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
SS 430 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 stainless steel 430 square tube weigh?
At the reference dimensions (a = 40 mm, t = 3 mm) a stainless steel 430 square tube of this size weighs 3.419 kg/m, or 2.297 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 stainless steel 430's density of 7,700 kg/m³ gives 3.419 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 stainless steel 430 weigh more or less than steel?
It is lighter than carbon steel for the same section — about 2 % lighter at 7,700 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 0.9809× 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 ss 430 square tube weigh the same as a ss 430 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 SS 430 weight or carbon steel weight for costing?
Use the material you are actually buying. At 7,700 kg/m³ against carbon steel's 7,850 kg/m³, the same square tube differs by 1.9 % 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 SS 430 sections
The same density applied to every shape the site covers.
- SS 430 round bar — A = π/4 · d²
- SS 430 square bar — A = a²
- SS 430 hexagonal bar — A = (√3/2) · AF² ≈ 0.8660 · AF²
- SS 430 flat bar — A = w · t
- SS 430 plate — A = w · t
- SS 430 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 7,700 kg/m³ (ASTM A240 (UNS S43000)). 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.