Stainless Steel 316 Hexagonal Bar Weight

Mass per metre and per foot for stainless steel 316 hexagonal bar 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 23.9 kg (53.6 lb per 20 ft).

Mass / length
3.991kg/m
2.682 lb/ft
Cross-section
498.8mm²
0.7732 in²
Reference size
24mm
AF
Density
8,000kg/m³
0.2890 lb/in³
6 m / 20 ft length
23.9kg
53.6 lb

At the reference dimensions (AF = 24 mm) this section has a cross-sectional area of 498.8 mm², giving 3.991 kg/m (2.682 lb/ft). Against carbon steel's 7,850 kg/m³ that is +1.9 % — the same section in steel would be 3.916 kg/m.

Calculate your own dimensions → Pipe and hollow sections

Hexagonal Bar — formula and derivation

Area of a hexagonal bar

A = (√3/2) · AF² ≈ 0.8660 · AF²

A = (√3/2) × AF², where AF is the distance across flats (the wrench size), not across corners

Worked through with the default dimensions:

A = (√3/2) × AF²A = 0.866025 × 24²A = 0.866025 × 576.0A = 498.8 mm²
AF
Across flats (AF) — Distance between opposite flats — the size a spanner grips. Hex bar is ordered by AF, not by corner-to-corner.

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 3.9906 kg/m for the reference size above.

SS 316 hexagonal bar — size series

Stainless Steel 316 hexagonal bar — by across flats (af)
Across flats (AF) Cross-section Mass / length
5.0 mm 21.65 mm² · 0.0336 in² 0.173 kg/m · 0.116 lb/ft
6.0 mm 31.18 mm² · 0.0483 in² 0.249 kg/m · 0.168 lb/ft
8.0 mm 55.43 mm² · 0.0859 in² 0.443 kg/m · 0.298 lb/ft
10 mm 86.60 mm² · 0.1342 in² 0.693 kg/m · 0.466 lb/ft
12 mm 124.71 mm² · 0.1933 in² 0.998 kg/m · 0.670 lb/ft
14 mm 169.74 mm² · 0.2631 in² 1.358 kg/m · 0.912 lb/ft
17 mm 250.28 mm² · 0.3879 in² 2.002 kg/m · 1.345 lb/ft
19 mm 312.64 mm² · 0.4846 in² 2.501 kg/m · 1.681 lb/ft
22 mm 419.16 mm² · 0.6497 in² 3.353 kg/m · 2.253 lb/ft
24 mm 498.83 mm² · 0.7732 in² 3.991 kg/m · 2.682 lb/ft
27 mm 631.33 mm² · 0.9786 in² 5.051 kg/m · 3.394 lb/ft
32 mm 886.81 mm² · 1.3746 in² 7.094 kg/m · 4.767 lb/ft
36 mm 1,122.37 mm² · 1.7397 in² 8.979 kg/m · 6.034 lb/ft
41 mm 1,455.79 mm² · 2.2565 in² 11.646 kg/m · 7.826 lb/ft
46 mm 1,832.51 mm² · 2.8404 in² 14.660 kg/m · 9.851 lb/ft
50 mm 2,165.06 mm² · 3.3559 in² 17.321 kg/m · 11.639 lb/ft

Computed for SS 316 at 8000 kg/m³ (0.2890 lb/in³). ASTM A240 / A276 (UNS S31600).

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.

Imperial sizes

Hexagonal 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.

SS 316 — common inch hex bar (across flats)
Stock size Metric equivalent mm Cross-section Mass / length
1/4 in 6.35 34.92 mm² · 0.0541 in² 0.279 kg/m · 0.188 lb/ft
5/16 in 7.94 54.56 mm² · 0.0846 in² 0.437 kg/m · 0.293 lb/ft
3/8 in 9.52 78.57 mm² · 0.1218 in² 0.629 kg/m · 0.422 lb/ft
7/16 in 11.11 106.94 mm² · 0.1658 in² 0.856 kg/m · 0.575 lb/ft
1/2 in 12.70 139.68 mm² · 0.2165 in² 1.117 kg/m · 0.751 lb/ft
9/16 in 14.29 176.78 mm² · 0.2740 in² 1.414 kg/m · 0.950 lb/ft
5/8 in 15.88 218.25 mm² · 0.3383 in² 1.746 kg/m · 1.173 lb/ft
3/4 in 19.05 314.28 mm² · 0.4871 in² 2.514 kg/m · 1.690 lb/ft
7/8 in 22.22 427.77 mm² · 0.6631 in² 3.422 kg/m · 2.300 lb/ft
1 in 25.40 558.72 mm² · 0.8660 in² 4.470 kg/m · 3.004 lb/ft
1-1/4 in 31.75 873.01 mm² · 1.3532 in² 6.984 kg/m · 4.693 lb/ft
1-1/2 in 38.10 1,257.13 mm² · 1.9486 in² 10.057 kg/m · 6.758 lb/ft
2 in 50.80 2,234.90 mm² · 3.4641 in² 17.879 kg/m · 12.014 lb/ft

Stock sizes in inches, converted exactly at 25.4 mm per inch. Material: Stainless Steel 316 at 8000 kg/m³.

The same hexagonal 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 316 is highlighted. The percentage column is against carbon steel, which is the figure most quotations are built on.

Hexagonal Bar at AF = 24 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 3.916 2.631 +0.0 %
Stainless Steel 304 8,000 0.2890 3.991 2.682 +1.9 %
Stainless Steel 316 8,000 0.2890 3.991 2.682 +1.9 %
Stainless Steel 316L 8,000 0.2890 3.991 2.682 +1.9 %
Stainless Steel 430 7,700 0.2782 3.841 2.581 -1.9 %
Aluminum 6061-T6 2,700 0.0975 1.347 0.905 -65.6 %
Aluminum 5052-H32 2,680 0.0968 1.337 0.898 -65.9 %
Aluminum 7075-T6 2,810 0.1015 1.402 0.942 -64.2 %
Copper C11000 8,940 0.3230 4.460 2.997 +13.9 %
Brass C36000 8,500 0.3071 4.240 2.849 +8.3 %
Bronze C93200 8,800 0.3179 4.390 2.950 +12.1 %
Titanium Grade 2 4,510 0.1629 2.250 1.512 -42.5 %
Gray Cast Iron 7,200 0.2601 3.592 2.413 -8.3 %
Lead 11,340 0.4097 5.657 3.801 +44.5 %
Rigid PVC (Type I) 1,400 0.0506 0.698 0.469 -82.2 %
HDPE (PE 100) 960 0.0347 0.479 0.322 -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 hexagonal bar

Hex bar is the one shape where the ordering dimension is not the dimension the formula wants. Stock is sold by across-flats (AF) because that is what the wrench grips, but the area formula needs AF as well — and the two are easy to confuse once a drawing quotes across-corners instead. Across-corners is a factor of 2/√3 (1.1547) larger than AF, so mixing them up inflates the calculated weight by 33 %. Always check which one the drawing calls out.

When ordering

Specified by across-flats. Say so explicitly on the order — "across corners" gives a different bar.

Download this data

SS 316 hexagonal bar — CSV

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Frequently asked questions

How much does stainless steel 316 hexagonal bar weigh?

At the reference dimensions (AF = 24 mm) a stainless steel 316 hexagonal bar of this size weighs 3.991 kg/m, or 2.682 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 hexagonal bar calculated?

Weight is cross-sectional area × length × density. For this shape the area is A = (√3/2) · AF² ≈ 0.8660 · AF². At the reference dimensions that gives 498.8 mm², and multiplying by stainless steel 316's density of 8,000 kg/m³ gives 3.991 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 hexagonal 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 hexagonal 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 498.8 mm² (0.7732 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 hexagonal bar 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 hexagonal 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 3.916 kg/m for comparison.

Other materials, same hexagonal bar

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

Hexagonal Bar area from A = (√3/2) · AF² ≈ 0.8660 · AF². 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.