SpecBase

Stainless Steel 316 Round Tube Weight

Mass per metre and per foot for stainless steel 316 round tube at 8,000 kg/m³ (ASTM A240 / A276 (UNS S31600)). Every figure is for the section as drawn. A 6 m length of this size weighs 21.3 kg (47.6 lb per 20 ft).

Mass / length
3.544kg/m
2.381 lb/ft
Cross-section
443.0mm²
0.6866 in²
Reference size
50 × 3mm
D, t
Density
8,000kg/m³
0.2890 lb/in³
6 m / 20 ft length
21.3kg
47.6 lb

At the reference dimensions (D = 50 mm, t = 3 mm) this section has a cross-sectional area of 443.0 mm², giving 3.544 kg/m (2.381 lb/ft). Against carbon steel's 7,850 kg/m³ that is +1.9 % — 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 8,000 kg/m³ that is 3.5437 kg/m for the reference size above.

SS 316 round tube — size series

SS 316 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 0.276 kg/m · 0.186 lb/ft 0.396 kg/m · 0.266 lb/ft 0.503 kg/m · 0.338 lb/ft 0.679 kg/m · 0.456 lb/ft 0.804 kg/m · 0.540 lb/ft 0.880 kg/m · 0.591 lb/ft 0.905 kg/m · 0.608 lb/ft 0.804 kg/m · 0.540 lb/ft
16 mm 0.377 kg/m · 0.253 lb/ft 0.547 kg/m · 0.367 lb/ft 0.704 kg/m · 0.473 lb/ft 0.980 kg/m · 0.659 lb/ft 1.206 kg/m · 0.811 lb/ft 1.382 kg/m · 0.929 lb/ft 1.508 kg/m · 1.013 lb/ft 1.608 kg/m · 1.081 lb/ft
20 mm 0.478 kg/m · 0.321 lb/ft 0.697 kg/m · 0.469 lb/ft 0.905 kg/m · 0.608 lb/ft 1.282 kg/m · 0.861 lb/ft 1.608 kg/m · 1.081 lb/ft 1.885 kg/m · 1.267 lb/ft 2.111 kg/m · 1.419 lb/ft 2.413 kg/m · 1.621 lb/ft
25 mm 0.603 kg/m · 0.405 lb/ft 0.886 kg/m · 0.595 lb/ft 1.156 kg/m · 0.777 lb/ft 1.659 kg/m · 1.115 lb/ft 2.111 kg/m · 1.419 lb/ft 2.513 kg/m · 1.689 lb/ft 2.865 kg/m · 1.925 lb/ft 3.418 kg/m · 2.297 lb/ft
32 mm 0.779 kg/m · 0.524 lb/ft 1.150 kg/m · 0.773 lb/ft 1.508 kg/m · 1.013 lb/ft 2.187 kg/m · 1.469 lb/ft 2.815 kg/m · 1.892 lb/ft 3.393 kg/m · 2.280 lb/ft 3.921 kg/m · 2.635 lb/ft 4.825 kg/m · 3.243 lb/ft
40 mm 0.980 kg/m · 0.659 lb/ft 1.451 kg/m · 0.975 lb/ft 1.910 kg/m · 1.284 lb/ft 2.790 kg/m · 1.875 lb/ft 3.619 kg/m · 2.432 lb/ft 4.398 kg/m · 2.955 lb/ft 5.127 kg/m · 3.445 lb/ft 6.434 kg/m · 4.323 lb/ft
50 mm 1.232 kg/m · 0.828 lb/ft 1.828 kg/m · 1.229 lb/ft 2.413 kg/m · 1.621 lb/ft 3.544 kg/m · 2.381 lb/ft 4.624 kg/m · 3.107 lb/ft 5.655 kg/m · 3.800 lb/ft 6.635 kg/m · 4.459 lb/ft 8.445 kg/m · 5.675 lb/ft
63 mm 1.558 kg/m · 1.047 lb/ft 2.318 kg/m · 1.558 lb/ft 3.066 kg/m · 2.060 lb/ft 4.524 kg/m · 3.040 lb/ft 5.931 kg/m · 3.986 lb/ft 7.288 kg/m · 4.898 lb/ft 8.595 kg/m · 5.776 lb/ft 11.058 kg/m · 7.431 lb/ft
76 mm 1.885 kg/m · 1.267 lb/ft 2.809 kg/m · 1.887 lb/ft 3.720 kg/m · 2.499 lb/ft 5.504 kg/m · 3.699 lb/ft 7.238 kg/m · 4.864 lb/ft 8.922 kg/m · 5.995 lb/ft 10.556 kg/m · 7.093 lb/ft 13.672 kg/m · 9.187 lb/ft
89 mm 2.212 kg/m · 1.486 lb/ft 3.299 kg/m · 2.217 lb/ft 4.373 kg/m · 2.939 lb/ft 6.484 kg/m · 4.357 lb/ft 8.545 kg/m · 5.742 lb/ft 10.556 kg/m · 7.093 lb/ft 12.516 kg/m · 8.410 lb/ft 16.286 kg/m · 10.944 lb/ft
114 mm 2.840 kg/m · 1.908 lb/ft 4.241 kg/m · 2.850 lb/ft 5.630 kg/m · 3.783 lb/ft 8.369 kg/m · 5.624 lb/ft 11.058 kg/m · 7.431 lb/ft 13.697 kg/m · 9.204 lb/ft 16.286 kg/m · 10.944 lb/ft 21.313 kg/m · 14.321 lb/ft
168 mm 4.197 kg/m · 2.820 lb/ft 6.277 kg/m · 4.218 lb/ft 8.344 kg/m · 5.607 lb/ft 12.441 kg/m · 8.360 lb/ft 16.487 kg/m · 11.079 lb/ft 20.483 kg/m · 13.764 lb/ft 24.429 kg/m · 16.416 lb/ft 32.170 kg/m · 21.617 lb/ft

Rows: outside diameter (mm). Columns: wall thickness (mm). Computed for Stainless Steel 316 at 8000 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. Stainless Steel 316 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 stainless steel 316

Identical density to 304, so weight tables can be shared between them — but not material selection. The 2–3 % molybdenum addition is what buys resistance to chlorides and to the sulphuric and acetic acid environments that pit 304. For a weight take-off the two are interchangeable; for a coastal or process-chemical application they are not, and the substitution is usually made for the wrong reason (availability) without recalculating corrosion allowance.

Density
8,000 kg/m³ = 0.2890 lb/in³ · 1.0191× carbon steel · typical spread ±1 %
Specification
ASTM A240 / A276 (UNS S31600)
Equivalents
EN 1.4401 · JIS SUS316 · GB 06Cr17Ni12Mo2
Typical uses
Marine and coastal hardware · Pharmaceutical and dairy process plant · Chemical storage and pipework · Pulp and paper

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.

Download this data

SS 316 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 stainless steel 316 round tube weigh?

At the reference dimensions (D = 50 mm, t = 3 mm) a stainless steel 316 round tube of this size weighs 3.544 kg/m, or 2.381 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 stainless steel 316's density of 8,000 kg/m³ gives 3.544 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 316 weigh more or less than steel?

It is heavier than carbon steel for the same section — about 2 % heavier at 8,000 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 1.0191× 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 ss 316 round tube weigh the same as a ss 316 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 316 weight or carbon steel weight for costing?

Use the material you are actually buying. At 8,000 kg/m³ against carbon steel's 7,850 kg/m³, the same round 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 3.477 kg/m for comparison.

Other materials, same round tube

The same geometry in every material, so the only variable is density.

Other SS 316 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 8,000 kg/m³ (ASTM A240 / A276 (UNS S31600)). 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.