HDPE (PE 100) Flat Bar Weight
Mass per metre and per foot for hdpe (pe 100) flat bar at 960 kg/m³ (ISO 4427 / ASTM D3350 (PE 100 black)). Every figure is for the section as drawn. A 6 m length of this size weighs 1.7 kg (3.9 lb per 20 ft).
At the reference dimensions (w = 50 mm, t = 6 mm) this section has a cross-sectional area of 300.0 mm², giving 0.288 kg/m (0.194 lb/ft). Against carbon steel's 7,850 kg/m³ that is -87.8 % — the same section in steel would be 2.355 kg/m.
Flat Bar — formula and derivation
Area of a flat bar
A = w · t
A = w × t, where w is width and t is thickness
Worked through with the default dimensions:
A = w × tA = 50 × 6A = 300.0 mm²
- w
- Width
- t
- Thickness
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 960 kg/m³ that is 0.2880 kg/m for the reference size above.
HDPE flat bar — size series
| Width | 3.0 | 4.0 | 5.0 | 6.0 | 8.0 | 10 | 12 | 16 | 20 |
|---|---|---|---|---|---|---|---|---|---|
| 12 mm | 0.035 kg/m · 0.023 lb/ft | 0.046 kg/m · 0.031 lb/ft | 0.058 kg/m · 0.039 lb/ft | 0.069 kg/m · 0.046 lb/ft | 0.092 kg/m · 0.062 lb/ft | 0.115 kg/m · 0.077 lb/ft | 0.138 kg/m · 0.093 lb/ft | 0.184 kg/m · 0.124 lb/ft | 0.230 kg/m · 0.155 lb/ft |
| 16 mm | 0.046 kg/m · 0.031 lb/ft | 0.061 kg/m · 0.041 lb/ft | 0.077 kg/m · 0.052 lb/ft | 0.092 kg/m · 0.062 lb/ft | 0.123 kg/m · 0.083 lb/ft | 0.154 kg/m · 0.103 lb/ft | 0.184 kg/m · 0.124 lb/ft | 0.246 kg/m · 0.165 lb/ft | 0.307 kg/m · 0.206 lb/ft |
| 20 mm | 0.058 kg/m · 0.039 lb/ft | 0.077 kg/m · 0.052 lb/ft | 0.096 kg/m · 0.065 lb/ft | 0.115 kg/m · 0.077 lb/ft | 0.154 kg/m · 0.103 lb/ft | 0.192 kg/m · 0.129 lb/ft | 0.230 kg/m · 0.155 lb/ft | 0.307 kg/m · 0.206 lb/ft | 0.384 kg/m · 0.258 lb/ft |
| 25 mm | 0.072 kg/m · 0.048 lb/ft | 0.096 kg/m · 0.065 lb/ft | 0.120 kg/m · 0.081 lb/ft | 0.144 kg/m · 0.097 lb/ft | 0.192 kg/m · 0.129 lb/ft | 0.240 kg/m · 0.161 lb/ft | 0.288 kg/m · 0.194 lb/ft | 0.384 kg/m · 0.258 lb/ft | 0.480 kg/m · 0.323 lb/ft |
| 30 mm | 0.086 kg/m · 0.058 lb/ft | 0.115 kg/m · 0.077 lb/ft | 0.144 kg/m · 0.097 lb/ft | 0.173 kg/m · 0.116 lb/ft | 0.230 kg/m · 0.155 lb/ft | 0.288 kg/m · 0.194 lb/ft | 0.346 kg/m · 0.232 lb/ft | 0.461 kg/m · 0.310 lb/ft | 0.576 kg/m · 0.387 lb/ft |
| 40 mm | 0.115 kg/m · 0.077 lb/ft | 0.154 kg/m · 0.103 lb/ft | 0.192 kg/m · 0.129 lb/ft | 0.230 kg/m · 0.155 lb/ft | 0.307 kg/m · 0.206 lb/ft | 0.384 kg/m · 0.258 lb/ft | 0.461 kg/m · 0.310 lb/ft | 0.614 kg/m · 0.413 lb/ft | 0.768 kg/m · 0.516 lb/ft |
| 50 mm | 0.144 kg/m · 0.097 lb/ft | 0.192 kg/m · 0.129 lb/ft | 0.240 kg/m · 0.161 lb/ft | 0.288 kg/m · 0.194 lb/ft | 0.384 kg/m · 0.258 lb/ft | 0.480 kg/m · 0.323 lb/ft | 0.576 kg/m · 0.387 lb/ft | 0.768 kg/m · 0.516 lb/ft | 0.960 kg/m · 0.645 lb/ft |
| 60 mm | 0.173 kg/m · 0.116 lb/ft | 0.230 kg/m · 0.155 lb/ft | 0.288 kg/m · 0.194 lb/ft | 0.346 kg/m · 0.232 lb/ft | 0.461 kg/m · 0.310 lb/ft | 0.576 kg/m · 0.387 lb/ft | 0.691 kg/m · 0.464 lb/ft | 0.922 kg/m · 0.619 lb/ft | 1.152 kg/m · 0.774 lb/ft |
| 80 mm | 0.230 kg/m · 0.155 lb/ft | 0.307 kg/m · 0.206 lb/ft | 0.384 kg/m · 0.258 lb/ft | 0.461 kg/m · 0.310 lb/ft | 0.614 kg/m · 0.413 lb/ft | 0.768 kg/m · 0.516 lb/ft | 0.922 kg/m · 0.619 lb/ft | 1.229 kg/m · 0.826 lb/ft | 1.536 kg/m · 1.032 lb/ft |
| 100 mm | 0.288 kg/m · 0.194 lb/ft | 0.384 kg/m · 0.258 lb/ft | 0.480 kg/m · 0.323 lb/ft | 0.576 kg/m · 0.387 lb/ft | 0.768 kg/m · 0.516 lb/ft | 0.960 kg/m · 0.645 lb/ft | 1.152 kg/m · 0.774 lb/ft | 1.536 kg/m · 1.032 lb/ft | 1.920 kg/m · 1.290 lb/ft |
Rows: width (mm). Columns: thickness (mm). Computed for HDPE (PE 100) at 960 kg/m³.
| Width | 3.0 | 4.0 | 5.0 | 6.0 | 8.0 | 10 | 12 | 16 | 20 |
|---|---|---|---|---|---|---|---|---|---|
| 12 mm | 36.0 | 48.0 | 60.0 | 72.0 | 96.0 | 120.0 | 144.0 | 192.0 | 240.0 |
| 16 mm | 48.0 | 64.0 | 80.0 | 96.0 | 128.0 | 160.0 | 192.0 | 256.0 | 320.0 |
| 20 mm | 60.0 | 80.0 | 100.0 | 120.0 | 160.0 | 200.0 | 240.0 | 320.0 | 400.0 |
| 25 mm | 75.0 | 100.0 | 125.0 | 150.0 | 200.0 | 250.0 | 300.0 | 400.0 | 500.0 |
| 30 mm | 90.0 | 120.0 | 150.0 | 180.0 | 240.0 | 300.0 | 360.0 | 480.0 | 600.0 |
| 40 mm | 120.0 | 160.0 | 200.0 | 240.0 | 320.0 | 400.0 | 480.0 | 640.0 | 800.0 |
| 50 mm | 150.0 | 200.0 | 250.0 | 300.0 | 400.0 | 500.0 | 600.0 | 800.0 | 1,000.0 |
| 60 mm | 180.0 | 240.0 | 300.0 | 360.0 | 480.0 | 600.0 | 720.0 | 960.0 | 1,200.0 |
| 80 mm | 240.0 | 320.0 | 400.0 | 480.0 | 640.0 | 800.0 | 960.0 | 1,280.0 | 1,600.0 |
| 100 mm | 300.0 | 400.0 | 500.0 | 600.0 | 800.0 | 1,000.0 | 1,200.0 | 1,600.0 | 2,000.0 |
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 flat bar in every material
Geometry is fixed and only density changes, so this table is the whole material-selection question in one view. HDPE (PE 100) 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 | 2.355 | 1.582 | +0.0 % |
| Stainless Steel 304 | 8,000 | 0.2890 | 2.400 | 1.613 | +1.9 % |
| Stainless Steel 316 | 8,000 | 0.2890 | 2.400 | 1.613 | +1.9 % |
| Stainless Steel 316L | 8,000 | 0.2890 | 2.400 | 1.613 | +1.9 % |
| Stainless Steel 430 | 7,700 | 0.2782 | 2.310 | 1.552 | -1.9 % |
| Aluminum 6061-T6 | 2,700 | 0.0975 | 0.810 | 0.544 | -65.6 % |
| Aluminum 5052-H32 | 2,680 | 0.0968 | 0.804 | 0.540 | -65.9 % |
| Aluminum 7075-T6 | 2,810 | 0.1015 | 0.843 | 0.566 | -64.2 % |
| Copper C11000 | 8,940 | 0.3230 | 2.682 | 1.802 | +13.9 % |
| Brass C36000 | 8,500 | 0.3071 | 2.550 | 1.714 | +8.3 % |
| Bronze C93200 | 8,800 | 0.3179 | 2.640 | 1.774 | +12.1 % |
| Titanium Grade 2 | 4,510 | 0.1629 | 1.353 | 0.909 | -42.5 % |
| Gray Cast Iron | 7,200 | 0.2601 | 2.160 | 1.451 | -8.3 % |
| Lead | 11,340 | 0.4097 | 3.402 | 2.286 | +44.5 % |
| Rigid PVC (Type I) | 1,400 | 0.0506 | 0.420 | 0.282 | -82.2 % |
| HDPE (PE 100) | 960 | 0.0347 | 0.288 | 0.194 | -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 hdpe (pe 100)
High-density polyethylene and the lightest material in the catalogue at 960 kg/m³ — it floats. That is not a curiosity: buoyancy governs how submerged outfall and intake lines are installed, and HDPE’s ability to be towed and floated into place in long strings is why it displaced steel for marine pipelines. It is also tougher than PVC at low temperature and tolerates ground movement without cracking, at the cost of much lower pressure rating at the same wall thickness.
- Density
- 960 kg/m³ = 0.0347 lb/in³ · 0.1223× carbon steel · typical spread ±2 %
- Specification
- ISO 4427 / ASTM D3350 (PE 100 black)
- Equivalents
- EN PE 100 · JIS PE100 · GB PE100
- Typical uses
- Water and gas mains · Submarine outfall lines · Landfill and leachate pipe · Geomembrane and lining
Density splits into two families: PE 100 pipe grades 950–960 kg/m³, PE 63/80 grades 930–945 kg/m³. Black compound includes ~2 % carbon black.
About flat bar
Flat bar is where the site’s most common estimating mistake shows up: weight is independent of how the bar is oriented, but stiffness is not. A 50 × 6 flat bent about its strong axis is roughly 69 times stiffer than the same bar bent about its weak axis, while both weigh 2.36 kg/m. Reading weight off a flat-bar table tells you what to order; it tells you nothing about whether the section will carry the load.
Specified as width × thickness. Edge condition (square, radiused, or sheared) changes the effective area slightly, not the nominal weight.
Download this data
HDPE flat 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 hdpe (pe 100) flat bar weigh?
At the reference dimensions (w = 50 mm, t = 6 mm) a hdpe (pe 100) flat bar of this size weighs 0.288 kg/m, or 0.194 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 flat bar calculated?
Weight is cross-sectional area × length × density. For this shape the area is A = w · t. At the reference dimensions that gives 300.0 mm², and multiplying by hdpe (pe 100)'s density of 960 kg/m³ gives 0.288 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 hdpe (pe 100) weigh more or less than steel?
It is lighter than carbon steel for the same section — about 88 % lighter at 960 kg/m³. Density is the only variable: the cross-sectional area depends purely on geometry, so a flat 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 0.1223× carbon steel.
What is the cross-sectional area of a flat 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 300.0 mm² (0.4650 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 hdpe flat bar weigh the same as a hdpe 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 HDPE weight or carbon steel weight for costing?
Use the material you are actually buying. At 960 kg/m³ against carbon steel's 7,850 kg/m³, the same flat bar differs by 87.8 % 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 2.355 kg/m for comparison.
Other materials, same flat bar
The same geometry in every material, so the only variable is density.
- Carbon steel flat bar — 7850 kg/m³
- SS 304 flat bar — 8000 kg/m³
- SS 316 flat bar — 8000 kg/m³
- AL 6061 flat bar — 2700 kg/m³
- Copper flat bar — 8940 kg/m³
- Brass flat bar — 8500 kg/m³
- PVC flat bar — 1400 kg/m³
- AL 5052 flat bar — 2680 kg/m³
Other HDPE sections
The same density applied to every shape the site covers.
- HDPE round bar — A = π/4 · d²
- HDPE square bar — A = a²
- HDPE hexagonal bar — A = (√3/2) · AF² ≈ 0.8660 · AF²
- HDPE plate — A = w · t
- HDPE round tube — A = π/4 · (D² − d²), d = D − 2t
- HDPE 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
Flat Bar area from A = w · t. Mass computed as area × length × density at 960 kg/m³ (ISO 4427 / ASTM D3350 (PE 100 black)). 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.