Aluminum 6061-T6 Round Tube Weight
Mass per metre and per foot for aluminum 6061-t6 round tube at 2,700 kg/m³ (ASTM B221 / B209 (T6 temper)). Every figure is for the section as drawn. A 6 m length of this size weighs 7.2 kg (16.1 lb per 20 ft).
At the reference dimensions (D = 50 mm, t = 3 mm) this section has a cross-sectional area of 443.0 mm², giving 1.196 kg/m (0.804 lb/ft). Against carbon steel's 7,850 kg/m³ that is -65.6 % — the same section in steel would be 3.477 kg/m.
Round Tube — formula and derivation
Area of a round tube
A = π/4 · (D² − d²), d = D − 2t
A = π/4 × (D² − d²), where D is the outside diameter, d the inside diameter, and d = D − 2t for wall thickness t
Worked through with the default dimensions:
A = π/4 × (D² − d²)d = 50 − 2 × 3 = 44.0 mmA = 0.785398 × (50² − 44.0²)A = 0.785398 × 564.0A = 443.0 mm²
- D
- Outside diameter
- t
- Wall thickness — Must be less than half the outside diameter.
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 2,700 kg/m³ that is 1.1960 kg/m for the reference size above.
AL 6061 round tube — size series
| Outside diameter | 1.0 | 1.5 | 2.0 | 3.0 | 4.0 | 5.0 | 6.0 | 8.0 |
|---|---|---|---|---|---|---|---|---|
| 12 mm | 0.093 kg/m · 0.063 lb/ft | 0.134 kg/m · 0.090 lb/ft | 0.170 kg/m · 0.114 lb/ft | 0.229 kg/m · 0.154 lb/ft | 0.271 kg/m · 0.182 lb/ft | 0.297 kg/m · 0.199 lb/ft | 0.305 kg/m · 0.205 lb/ft | 0.271 kg/m · 0.182 lb/ft |
| 16 mm | 0.127 kg/m · 0.085 lb/ft | 0.184 kg/m · 0.124 lb/ft | 0.238 kg/m · 0.160 lb/ft | 0.331 kg/m · 0.222 lb/ft | 0.407 kg/m · 0.274 lb/ft | 0.467 kg/m · 0.313 lb/ft | 0.509 kg/m · 0.342 lb/ft | 0.543 kg/m · 0.365 lb/ft |
| 20 mm | 0.161 kg/m · 0.108 lb/ft | 0.235 kg/m · 0.158 lb/ft | 0.305 kg/m · 0.205 lb/ft | 0.433 kg/m · 0.291 lb/ft | 0.543 kg/m · 0.365 lb/ft | 0.636 kg/m · 0.427 lb/ft | 0.713 kg/m · 0.479 lb/ft | 0.814 kg/m · 0.547 lb/ft |
| 25 mm | 0.204 kg/m · 0.137 lb/ft | 0.299 kg/m · 0.201 lb/ft | 0.390 kg/m · 0.262 lb/ft | 0.560 kg/m · 0.376 lb/ft | 0.713 kg/m · 0.479 lb/ft | 0.848 kg/m · 0.570 lb/ft | 0.967 kg/m · 0.650 lb/ft | 1.154 kg/m · 0.775 lb/ft |
| 32 mm | 0.263 kg/m · 0.177 lb/ft | 0.388 kg/m · 0.261 lb/ft | 0.509 kg/m · 0.342 lb/ft | 0.738 kg/m · 0.496 lb/ft | 0.950 kg/m · 0.638 lb/ft | 1.145 kg/m · 0.769 lb/ft | 1.323 kg/m · 0.889 lb/ft | 1.629 kg/m · 1.094 lb/ft |
| 40 mm | 0.331 kg/m · 0.222 lb/ft | 0.490 kg/m · 0.329 lb/ft | 0.645 kg/m · 0.433 lb/ft | 0.942 kg/m · 0.633 lb/ft | 1.221 kg/m · 0.821 lb/ft | 1.484 kg/m · 0.997 lb/ft | 1.730 kg/m · 1.163 lb/ft | 2.171 kg/m · 1.459 lb/ft |
| 50 mm | 0.416 kg/m · 0.279 lb/ft | 0.617 kg/m · 0.415 lb/ft | 0.814 kg/m · 0.547 lb/ft | 1.196 kg/m · 0.804 lb/ft | 1.561 kg/m · 1.049 lb/ft | 1.909 kg/m · 1.282 lb/ft | 2.239 kg/m · 1.505 lb/ft | 2.850 kg/m · 1.915 lb/ft |
| 63 mm | 0.526 kg/m · 0.353 lb/ft | 0.782 kg/m · 0.526 lb/ft | 1.035 kg/m · 0.695 lb/ft | 1.527 kg/m · 1.026 lb/ft | 2.002 kg/m · 1.345 lb/ft | 2.460 kg/m · 1.653 lb/ft | 2.901 kg/m · 1.949 lb/ft | 3.732 kg/m · 2.508 lb/ft |
| 76 mm | 0.636 kg/m · 0.427 lb/ft | 0.948 kg/m · 0.637 lb/ft | 1.255 kg/m · 0.844 lb/ft | 1.858 kg/m · 1.248 lb/ft | 2.443 kg/m · 1.642 lb/ft | 3.011 kg/m · 2.023 lb/ft | 3.563 kg/m · 2.394 lb/ft | 4.614 kg/m · 3.101 lb/ft |
| 89 mm | 0.746 kg/m · 0.502 lb/ft | 1.113 kg/m · 0.748 lb/ft | 1.476 kg/m · 0.992 lb/ft | 2.188 kg/m · 1.471 lb/ft | 2.884 kg/m · 1.938 lb/ft | 3.563 kg/m · 2.394 lb/ft | 4.224 kg/m · 2.839 lb/ft | 5.497 kg/m · 3.693 lb/ft |
| 114 mm | 0.958 kg/m · 0.644 lb/ft | 1.431 kg/m · 0.962 lb/ft | 1.900 kg/m · 1.277 lb/ft | 2.825 kg/m · 1.898 lb/ft | 3.732 kg/m · 2.508 lb/ft | 4.623 kg/m · 3.106 lb/ft | 5.497 kg/m · 3.693 lb/ft | 7.193 kg/m · 4.833 lb/ft |
| 168 mm | 1.417 kg/m · 0.952 lb/ft | 2.118 kg/m · 1.424 lb/ft | 2.816 kg/m · 1.892 lb/ft | 4.199 kg/m · 2.821 lb/ft | 5.564 kg/m · 3.739 lb/ft | 6.913 kg/m · 4.645 lb/ft | 8.245 kg/m · 5.540 lb/ft | 10.857 kg/m · 7.296 lb/ft |
Rows: outside diameter (mm). Columns: wall thickness (mm). Computed for Aluminum 6061-T6 at 2700 kg/m³.
| Outside diameter | 1.0 | 1.5 | 2.0 | 3.0 | 4.0 | 5.0 | 6.0 | 8.0 |
|---|---|---|---|---|---|---|---|---|
| 12 mm | 34.6 | 49.5 | 62.8 | 84.8 | 100.5 | 110.0 | 113.1 | 100.5 |
| 16 mm | 47.1 | 68.3 | 88.0 | 122.5 | 150.8 | 172.8 | 188.5 | 201.1 |
| 20 mm | 59.7 | 87.2 | 113.1 | 160.2 | 201.1 | 235.6 | 263.9 | 301.6 |
| 25 mm | 75.4 | 110.7 | 144.5 | 207.3 | 263.9 | 314.2 | 358.1 | 427.3 |
| 32 mm | 97.4 | 143.7 | 188.5 | 273.3 | 351.9 | 424.1 | 490.1 | 603.2 |
| 40 mm | 122.5 | 181.4 | 238.8 | 348.7 | 452.4 | 549.8 | 640.9 | 804.2 |
| 50 mm | 153.9 | 228.6 | 301.6 | 443.0 | 578.1 | 706.9 | 829.4 | 1,055.6 |
| 63 mm | 194.8 | 289.8 | 383.3 | 565.5 | 741.4 | 911.1 | 1,074.4 | 1,382.3 |
| 76 mm | 235.6 | 351.1 | 465.0 | 688.0 | 904.8 | 1,115.3 | 1,319.5 | 1,709.0 |
| 89 mm | 276.5 | 412.3 | 546.6 | 810.5 | 1,068.1 | 1,319.5 | 1,564.5 | 2,035.8 |
| 114 mm | 355.0 | 530.1 | 703.7 | 1,046.2 | 1,382.3 | 1,712.2 | 2,035.8 | 2,664.1 |
| 168 mm | 524.6 | 784.6 | 1,043.0 | 1,555.1 | 2,060.9 | 2,560.4 | 3,053.6 | 4,021.2 |
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 round tube in every material
Geometry is fixed and only density changes, so this table is the whole material-selection question in one view. Aluminum 6061-T6 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 | 3.477 | 2.337 | +0.0 % |
| Stainless Steel 304 | 8,000 | 0.2890 | 3.544 | 2.381 | +1.9 % |
| Stainless Steel 316 | 8,000 | 0.2890 | 3.544 | 2.381 | +1.9 % |
| Stainless Steel 316L | 8,000 | 0.2890 | 3.544 | 2.381 | +1.9 % |
| Stainless Steel 430 | 7,700 | 0.2782 | 3.411 | 2.292 | -1.9 % |
| Aluminum 6061-T6 | 2,700 | 0.0975 | 1.196 | 0.804 | -65.6 % |
| Aluminum 5052-H32 | 2,680 | 0.0968 | 1.187 | 0.798 | -65.9 % |
| Aluminum 7075-T6 | 2,810 | 0.1015 | 1.245 | 0.836 | -64.2 % |
| Copper C11000 | 8,940 | 0.3230 | 3.960 | 2.661 | +13.9 % |
| Brass C36000 | 8,500 | 0.3071 | 3.765 | 2.530 | +8.3 % |
| Bronze C93200 | 8,800 | 0.3179 | 3.898 | 2.619 | +12.1 % |
| Titanium Grade 2 | 4,510 | 0.1629 | 1.998 | 1.342 | -42.5 % |
| Gray Cast Iron | 7,200 | 0.2601 | 3.189 | 2.143 | -8.3 % |
| Lead | 11,340 | 0.4097 | 5.023 | 3.375 | +44.5 % |
| Rigid PVC (Type I) | 1,400 | 0.0506 | 0.620 | 0.417 | -82.2 % |
| HDPE (PE 100) | 960 | 0.0347 | 0.425 | 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 aluminum 6061-t6
The general-purpose structural aluminium: magnesium and silicon alloyed, precipitation-hardened to T6, readily welded and machined. At 2,700 kg/m³ it is 2.91 times lighter than carbon steel, which is the entire reason it gets specified — but designers routinely forget that its modulus is also only about a third of steel’s, so a straight aluminium-for-steel swap cuts mass by 66 % while roughly tripling deflection for the same section. Weight savings and stiffness are separate problems.
- Density
- 2,700 kg/m³ = 0.0975 lb/in³ · 0.3439× carbon steel · typical spread ±1 %
- Specification
- ASTM B221 / B209 (T6 temper)
- Equivalents
- EN AW-6061 · JIS A6061 · GB 6061
- Typical uses
- Aircraft and drone frames · Marine decking and masts · Machine guards and jigs · Truck and trailer bodies
About round tube
Hollow sections are the most efficient way to buy stiffness by weight, and the numbers are stark: a 50 mm outside diameter tube with a 3 mm wall has the same area as a 22.6 mm solid bar — about 20 % of the mass — but its second moment of area is roughly 2.4 times larger. The catch is local: a thin wall buckles and dents long before it yields, so tube is chosen for stiffness and stability, never for where impact or crushing is expected.
Specified as outside diameter × wall thickness. State the standard (e.g. EN 10219) and whether the tube is welded or seamless.
Download this data
AL 6061 round 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 aluminum 6061-t6 round tube weigh?
At the reference dimensions (D = 50 mm, t = 3 mm) a aluminum 6061-t6 round tube of this size weighs 1.196 kg/m, or 0.804 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 round tube calculated?
Weight is cross-sectional area × length × density. For this shape the area is A = π/4 · (D² − d²), d = D − 2t. At the reference dimensions that gives 443.0 mm², and multiplying by aluminum 6061-t6's density of 2,700 kg/m³ gives 1.196 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 aluminum 6061-t6 weigh more or less than steel?
It is lighter than carbon steel for the same section — about 66 % lighter at 2,700 kg/m³. Density is the only variable: the cross-sectional area depends purely on geometry, so a round 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 0.3439× carbon steel.
What is the cross-sectional area of a round 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 443.0 mm² (0.6866 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 al 6061 round tube weigh the same as a al 6061 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 AL 6061 weight or carbon steel weight for costing?
Use the material you are actually buying. At 2,700 kg/m³ against carbon steel's 7,850 kg/m³, the same round tube differs by 65.6 % 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 3.477 kg/m for comparison.
Other materials, same round tube
The same geometry in every material, so the only variable is density.
- Carbon steel round tube — 7850 kg/m³
- SS 304 round tube — 8000 kg/m³
- SS 316 round tube — 8000 kg/m³
- Copper round tube — 8940 kg/m³
- Brass round tube — 8500 kg/m³
- HDPE round tube — 960 kg/m³
- PVC round tube — 1400 kg/m³
- AL 5052 round tube — 2680 kg/m³
Other AL 6061 sections
The same density applied to every shape the site covers.
- AL 6061 round bar — A = π/4 · d²
- AL 6061 square bar — A = a²
- AL 6061 hexagonal bar — A = (√3/2) · AF² ≈ 0.8660 · AF²
- AL 6061 flat bar — A = w · t
- AL 6061 plate — A = w · t
- AL 6061 square tube — A = a² − (a − 2t)²
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
Round Tube area from A = π/4 · (D² − d²), d = D − 2t. Mass computed as area × length × density at 2,700 kg/m³ (ASTM B221 / B209 (T6 temper)). 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.