SpecBase

Brass C36000 Round Tube Weight

Mass per metre and per foot for brass c36000 round tube at 8,500 kg/m³ (ASTM B16 (UNS C36000, free-cutting)). Every figure is for the section as drawn. A 6 m length of this size weighs 22.6 kg (50.6 lb per 20 ft).

Mass / length
3.765kg/m
2.530 lb/ft
Cross-section
443.0mm²
0.6866 in²
Reference size
50 × 3mm
D, t
Density
8,500kg/m³
0.3071 lb/in³
6 m / 20 ft length
22.6kg
50.6 lb

At the reference dimensions (D = 50 mm, t = 3 mm) this section has a cross-sectional area of 443.0 mm², giving 3.765 kg/m (2.530 lb/ft). Against carbon steel's 7,850 kg/m³ that is +8.3 % — the same section in steel would be 3.477 kg/m.

Calculate your own dimensions → Pipe and hollow sections

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 8,500 kg/m³ that is 3.7652 kg/m for the reference size above.

Brass round tube — size series

Brass round tube — mass per unit length (kg/m · lb/ft)
Outside diameter 1.0 1.5 2.0 3.0 4.0 5.0 6.0 8.0
12 mm 0.294 kg/m · 0.197 lb/ft 0.421 kg/m · 0.283 lb/ft 0.534 kg/m · 0.359 lb/ft 0.721 kg/m · 0.484 lb/ft 0.855 kg/m · 0.574 lb/ft 0.935 kg/m · 0.628 lb/ft 0.961 kg/m · 0.646 lb/ft 0.855 kg/m · 0.574 lb/ft
16 mm 0.401 kg/m · 0.269 lb/ft 0.581 kg/m · 0.390 lb/ft 0.748 kg/m · 0.502 lb/ft 1.041 kg/m · 0.700 lb/ft 1.282 kg/m · 0.861 lb/ft 1.469 kg/m · 0.987 lb/ft 1.602 kg/m · 1.077 lb/ft 1.709 kg/m · 1.148 lb/ft
20 mm 0.507 kg/m · 0.341 lb/ft 0.741 kg/m · 0.498 lb/ft 0.961 kg/m · 0.646 lb/ft 1.362 kg/m · 0.915 lb/ft 1.709 kg/m · 1.148 lb/ft 2.003 kg/m · 1.346 lb/ft 2.243 kg/m · 1.507 lb/ft 2.564 kg/m · 1.723 lb/ft
25 mm 0.641 kg/m · 0.431 lb/ft 0.941 kg/m · 0.633 lb/ft 1.228 kg/m · 0.825 lb/ft 1.762 kg/m · 1.184 lb/ft 2.243 kg/m · 1.507 lb/ft 2.670 kg/m · 1.794 lb/ft 3.044 kg/m · 2.046 lb/ft 3.632 kg/m · 2.440 lb/ft
32 mm 0.828 kg/m · 0.556 lb/ft 1.222 kg/m · 0.821 lb/ft 1.602 kg/m · 1.077 lb/ft 2.323 kg/m · 1.561 lb/ft 2.991 kg/m · 2.010 lb/ft 3.605 kg/m · 2.422 lb/ft 4.166 kg/m · 2.799 lb/ft 5.127 kg/m · 3.445 lb/ft
40 mm 1.041 kg/m · 0.700 lb/ft 1.542 kg/m · 1.036 lb/ft 2.029 kg/m · 1.364 lb/ft 2.964 kg/m · 1.992 lb/ft 3.845 kg/m · 2.584 lb/ft 4.673 kg/m · 3.140 lb/ft 5.448 kg/m · 3.661 lb/ft 6.836 kg/m · 4.594 lb/ft
50 mm 1.308 kg/m · 0.879 lb/ft 1.943 kg/m · 1.305 lb/ft 2.564 kg/m · 1.723 lb/ft 3.765 kg/m · 2.530 lb/ft 4.913 kg/m · 3.302 lb/ft 6.008 kg/m · 4.037 lb/ft 7.050 kg/m · 4.737 lb/ft 8.972 kg/m · 6.029 lb/ft
63 mm 1.656 kg/m · 1.113 lb/ft 2.463 kg/m · 1.655 lb/ft 3.258 kg/m · 2.189 lb/ft 4.807 kg/m · 3.230 lb/ft 6.302 kg/m · 4.235 lb/ft 7.744 kg/m · 5.204 lb/ft 9.133 kg/m · 6.137 lb/ft 11.750 kg/m · 7.895 lb/ft
76 mm 2.003 kg/m · 1.346 lb/ft 2.984 kg/m · 2.005 lb/ft 3.952 kg/m · 2.656 lb/ft 5.848 kg/m · 3.930 lb/ft 7.691 kg/m · 5.168 lb/ft 9.480 kg/m · 6.370 lb/ft 11.215 kg/m · 7.536 lb/ft 14.527 kg/m · 9.762 lb/ft
89 mm 2.350 kg/m · 1.579 lb/ft 3.505 kg/m · 2.355 lb/ft 4.646 kg/m · 3.122 lb/ft 6.890 kg/m · 4.630 lb/ft 9.079 kg/m · 6.101 lb/ft 11.215 kg/m · 7.536 lb/ft 13.298 kg/m · 8.936 lb/ft 17.304 kg/m · 11.628 lb/ft
114 mm 3.017 kg/m · 2.028 lb/ft 4.506 kg/m · 3.028 lb/ft 5.982 kg/m · 4.019 lb/ft 8.892 kg/m · 5.975 lb/ft 11.750 kg/m · 7.895 lb/ft 14.553 kg/m · 9.779 lb/ft 17.304 kg/m · 11.628 lb/ft 22.645 kg/m · 15.216 lb/ft
168 mm 4.459 kg/m · 2.997 lb/ft 6.669 kg/m · 4.482 lb/ft 8.866 kg/m · 5.957 lb/ft 13.218 kg/m · 8.882 lb/ft 17.518 kg/m · 11.771 lb/ft 21.763 kg/m · 14.624 lb/ft 25.956 kg/m · 17.442 lb/ft 34.181 kg/m · 22.968 lb/ft

Rows: outside diameter (mm). Columns: wall thickness (mm). Computed for Brass C36000 at 8500 kg/m³.

Round Tube — cross-sectional area (mm²)
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.

How to read this table

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. Brass C36000 is highlighted. The percentage column is against carbon steel, which is the figure most quotations are built on.

Round Tube at D = 50 mm, t = 3 mm — mass in every material
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 brass c36000

Free-cutting brass, roughly 61 % copper and 3 % lead, and by a wide margin the most machinable common metal — it machines at about three times the speed of 1018 steel with excellent finish. Density 8,500 kg/m³ puts it 8.3 % above carbon steel. The lead that makes it machine so well is also why it is restricted in potable-water contact under many national rules, which pushes fittings toward lead-free silicon or bismuth brasses with densities 0.5–1 % lower.

Density
8,500 kg/m³ = 0.3071 lb/in³ · 1.0828× carbon steel · typical spread ±2 %
Specification
ASTM B16 (UNS C36000, free-cutting)
Equivalents
EN CW603N · JIS C3604 · GB HPb59-1
Typical uses
Fittings and valves · Instrument and clock parts · Electrical connectors · Decorative hardware
Weight-relevant caution

Lead content (typically 2.5–3.7 %) restricts use in potable water. Typical density range 8,400–8,700 kg/m³ by composition.

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.

When ordering

Specified as outside diameter × wall thickness. State the standard (e.g. EN 10219) and whether the tube is welded or seamless.

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Brass 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.

All materials (CSV · 16 × 10 pages)

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 brass c36000 round tube weigh?

At the reference dimensions (D = 50 mm, t = 3 mm) a brass c36000 round tube of this size weighs 3.765 kg/m, or 2.530 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 brass c36000's density of 8,500 kg/m³ gives 3.765 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 brass c36000 weigh more or less than steel?

It is heavier than carbon steel for the same section — about 8 % heavier at 8,500 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 1.0828× 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 brass round tube weigh the same as a brass 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 Brass weight or carbon steel weight for costing?

Use the material you are actually buying. At 8,500 kg/m³ against carbon steel's 7,850 kg/m³, the same round tube differs by 8.3 % 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.

Other Brass sections

The same density applied to every shape the site covers.

Reference data and tools

Data source and method

Round Tube area from A = π/4 · (D² − d²), d = D − 2t. Mass computed as area × length × density at 8,500 kg/m³ (ASTM B16 (UNS C36000, free-cutting)). 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.