Stainless Steel 304 Round Bar Weight
Mass per metre and per foot for stainless steel 304 round bar at 8,000 kg/m³ (ASTM A240 / A276 (UNS S30400)). Every figure is for the section as drawn. A 6 m length of this size weighs 23.6 kg (52.8 lb per 20 ft).
At the reference dimensions (d = 25 mm) this section has a cross-sectional area of 490.9 mm², giving 3.927 kg/m (2.639 lb/ft). Against carbon steel's 7,850 kg/m³ that is +1.9 % — the same section in steel would be 3.853 kg/m.
Round Bar — formula and derivation
Area of a round bar
A = π/4 · d²
A = π/4 × d², where d is the outside diameter
Worked through with the default dimensions:
A = π/4 × d²A = 0.785398 × 25²A = 0.785398 × 625.0A = 490.9 mm²
- d
- Diameter — Outside diameter measured across the bar.
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 3.9270 kg/m for the reference size above.
SS 304 round bar — size series
| Diameter | Cross-section | Mass / length |
|---|---|---|
| 6.0 mm | 28.27 mm² · 0.0438 in² | 0.226 kg/m · 0.152 lb/ft |
| 8.0 mm | 50.27 mm² · 0.0779 in² | 0.402 kg/m · 0.270 lb/ft |
| 10 mm | 78.54 mm² · 0.1217 in² | 0.628 kg/m · 0.422 lb/ft |
| 12 mm | 113.10 mm² · 0.1753 in² | 0.905 kg/m · 0.608 lb/ft |
| 14 mm | 153.94 mm² · 0.2386 in² | 1.232 kg/m · 0.828 lb/ft |
| 16 mm | 201.06 mm² · 0.3116 in² | 1.608 kg/m · 1.081 lb/ft |
| 20 mm | 314.16 mm² · 0.4869 in² | 2.513 kg/m · 1.689 lb/ft |
| 25 mm | 490.87 mm² · 0.7609 in² | 3.927 kg/m · 2.639 lb/ft |
| 30 mm | 706.86 mm² · 1.0956 in² | 5.655 kg/m · 3.800 lb/ft |
| 32 mm | 804.25 mm² · 1.2466 in² | 6.434 kg/m · 4.323 lb/ft |
| 40 mm | 1,256.64 mm² · 1.9478 in² | 10.053 kg/m · 6.755 lb/ft |
| 50 mm | 1,963.50 mm² · 3.0434 in² | 15.708 kg/m · 10.555 lb/ft |
| 60 mm | 2,827.43 mm² · 4.3825 in² | 22.619 kg/m · 15.200 lb/ft |
| 80 mm | 5,026.55 mm² · 7.7912 in² | 40.212 kg/m · 27.021 lb/ft |
| 100 mm | 7,853.98 mm² · 12.1737 in² | 62.832 kg/m · 42.221 lb/ft |
Computed for SS 304 at 8000 kg/m³ (0.2890 lb/in³). ASTM A240 / A276 (UNS S30400).
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.
Imperial sizes
Round Bar is also bought in inch sizes. The conversions below are exact (1 in = 25.4 mm by definition), so the metric equivalents are the true millimetre dimensions rather than a rounded nominal figure.
| Stock size | Metric equivalent mm | Cross-section | Mass / length |
|---|---|---|---|
| 1/8 in | 3.17 | 7.92 mm² · 0.0123 in² | 0.063 kg/m · 0.043 lb/ft |
| 3/16 in | 4.76 | 17.81 mm² · 0.0276 in² | 0.143 kg/m · 0.096 lb/ft |
| 1/4 in | 6.35 | 31.67 mm² · 0.0491 in² | 0.253 kg/m · 0.170 lb/ft |
| 5/16 in | 7.94 | 49.48 mm² · 0.0767 in² | 0.396 kg/m · 0.266 lb/ft |
| 3/8 in | 9.52 | 71.26 mm² · 0.1104 in² | 0.570 kg/m · 0.383 lb/ft |
| 1/2 in | 12.70 | 126.68 mm² · 0.1963 in² | 1.013 kg/m · 0.681 lb/ft |
| 5/8 in | 15.88 | 197.93 mm² · 0.3068 in² | 1.583 kg/m · 1.064 lb/ft |
| 3/4 in | 19.05 | 285.02 mm² · 0.4418 in² | 2.280 kg/m · 1.532 lb/ft |
| 7/8 in | 22.22 | 387.95 mm² · 0.6013 in² | 3.104 kg/m · 2.086 lb/ft |
| 1 in | 25.40 | 506.71 mm² · 0.7854 in² | 4.054 kg/m · 2.724 lb/ft |
| 1-1/4 in | 31.75 | 791.73 mm² · 1.2272 in² | 6.334 kg/m · 4.256 lb/ft |
| 1-1/2 in | 38.10 | 1,140.09 mm² · 1.7671 in² | 9.121 kg/m · 6.129 lb/ft |
| 2 in | 50.80 | 2,026.83 mm² · 3.1416 in² | 16.215 kg/m · 10.896 lb/ft |
| 2-1/2 in | 63.50 | 3,166.92 mm² · 4.9087 in² | 25.335 kg/m · 17.025 lb/ft |
| 3 in | 76.20 | 4,560.37 mm² · 7.0686 in² | 36.483 kg/m · 24.515 lb/ft |
| 4 in | 101.60 | 8,107.32 mm² · 12.5664 in² | 64.859 kg/m · 43.583 lb/ft |
Stock sizes in inches, converted exactly at 25.4 mm per inch. Material: Stainless Steel 304 at 8000 kg/m³.
The same round bar in every material
Geometry is fixed and only density changes, so this table is the whole material-selection question in one view. Stainless Steel 304 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 | 3.853 | 2.589 | +0.0 % |
| Stainless Steel 304 | 8,000 | 0.2890 | 3.927 | 2.639 | +1.9 % |
| Stainless Steel 316 | 8,000 | 0.2890 | 3.927 | 2.639 | +1.9 % |
| Stainless Steel 316L | 8,000 | 0.2890 | 3.927 | 2.639 | +1.9 % |
| Stainless Steel 430 | 7,700 | 0.2782 | 3.780 | 2.540 | -1.9 % |
| Aluminum 6061-T6 | 2,700 | 0.0975 | 1.325 | 0.891 | -65.6 % |
| Aluminum 5052-H32 | 2,680 | 0.0968 | 1.316 | 0.884 | -65.9 % |
| Aluminum 7075-T6 | 2,810 | 0.1015 | 1.379 | 0.927 | -64.2 % |
| Copper C11000 | 8,940 | 0.3230 | 4.388 | 2.949 | +13.9 % |
| Brass C36000 | 8,500 | 0.3071 | 4.172 | 2.804 | +8.3 % |
| Bronze C93200 | 8,800 | 0.3179 | 4.320 | 2.903 | +12.1 % |
| Titanium Grade 2 | 4,510 | 0.1629 | 2.214 | 1.488 | -42.5 % |
| Gray Cast Iron | 7,200 | 0.2601 | 3.534 | 2.375 | -8.3 % |
| Lead | 11,340 | 0.4097 | 5.567 | 3.741 | +44.5 % |
| Rigid PVC (Type I) | 1,400 | 0.0506 | 0.687 | 0.462 | -82.2 % |
| HDPE (PE 100) | 960 | 0.0347 | 0.471 | 0.317 | -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 304
The default austenitic stainless: 18 % chromium, 8 % nickel, non-magnetic in the annealed condition. At 8,000 kg/m³ it is 1.9 % heavier than carbon steel for an identical section, a difference large enough to matter on fabricated orders and small enough to be routinely forgotten. Machining work-hardens it, so heavy stock removal needs slower speeds and consistent feed than a 304 bar will forgive.
- Density
- 8,000 kg/m³ = 0.2890 lb/in³ · 1.0191× carbon steel · typical spread ±1 %
- Specification
- ASTM A240 / A276 (UNS S30400)
- Equivalents
- EN 1.4301 · JIS SUS304 · GB 06Cr19Ni10
- Typical uses
- Food and beverage equipment · Architectural handrail and trim · Sanitary tubing · General fasteners
Austenitic grades become slightly magnetic after cold work (drawn bar, formed tube). A magnet test is therefore not a valid grade check.
About round bar
Round bar is the only shape whose area grows with the square of a single dimension, so small diameter changes move weight much faster than intuition suggests: going from 25 mm to 28 mm — a 12 % diameter increase — raises the weight per metre by 25 %. This is why shaft stock is normally bought to the nearest preferred diameter rather than machined down from the next size up; the material saved is more than the weight table implies.
Specified by diameter only. For ground and polished stock, add the tolerance class and the straightness limit.
Download this data
SS 304 round bar — 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 304 round bar weigh?
At the reference dimensions (d = 25 mm) a stainless steel 304 round bar of this size weighs 3.927 kg/m, or 2.639 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 bar calculated?
Weight is cross-sectional area × length × density. For this shape the area is A = π/4 · d². At the reference dimensions that gives 490.9 mm², and multiplying by stainless steel 304's density of 8,000 kg/m³ gives 3.927 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 304 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 bar 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 bar?
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 490.9 mm² (0.7609 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 304 round bar weigh the same as a ss 304 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 304 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 bar 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 3.853 kg/m for comparison.
Other materials, same round bar
The same geometry in every material, so the only variable is density.
- Carbon steel round bar — 7850 kg/m³
- SS 316 round bar — 8000 kg/m³
- AL 6061 round bar — 2700 kg/m³
- Copper round bar — 8940 kg/m³
- Brass round bar — 8500 kg/m³
- HDPE round bar — 960 kg/m³
- PVC round bar — 1400 kg/m³
- AL 5052 round bar — 2680 kg/m³
Other SS 304 sections
The same density applied to every shape the site covers.
- SS 304 square bar — A = a²
- SS 304 hexagonal bar — A = (√3/2) · AF² ≈ 0.8660 · AF²
- SS 304 flat bar — A = w · t
- SS 304 plate — A = w · t
- SS 304 round tube — A = π/4 · (D² − d²), d = D − 2t
- SS 304 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 Bar area from A = π/4 · d². Mass computed as area × length × density at 8,000 kg/m³ (ASTM A240 / A276 (UNS S30400)). 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.