Tooling and hardware
Metal weight calculator
Weight = volume x density; a 2.000 in round 6061 aluminum bar 12.000 in long weighs 3.68 lb.
Technical review pending. Formulas and values are cited. This notice comes down after a machinist review.
Weight
lb
Weight = V x density x qty = 37.699 x 0.0975 x 1 = 3.68 lb
1.67 kg. Aluminum 6061, 0.0975 lb/in³. Nominal size and density.
Volume
in³
V = (pi / 4) x D^2 x L = (3.1416 / 4) x 2^2 x 12 = 37.699 in³
Source: Machinery's Handbook (densities of metals) and producer data sheets, listed under the density table; weight = volume x density.
How it works
Weight = V x density
| Symbol | Meaning | Unit |
|---|---|---|
| V | Volume of the piece | in³ or cm³ |
| density | Material density | lb/in³ or g/cm³ |
| D | Round bar diameter | in or mm |
| a | Side of a square bar | in or mm |
| AF | Hex bar across flats | in or mm |
| W, T | Width and thickness of flat bar or plate | in or mm |
| OD, ID | Tube outside and inside diameter | in or mm |
| W, H, t | Rectangular tube width, height and wall | in or mm |
| L | Length | in or mm |
| qty | Number of pieces | pcs |
| Shape | Volume formula |
|---|---|
| Round bar | V = (pi / 4) x D^2 x L |
| Square bar | V = a^2 x L |
| Hex bar | V = 0.866025 x AF^2 x L |
| Flat bar or plate | V = W x T x L |
| Round tube | V = (pi / 4) x (OD^2 - ID^2) x L |
| Rectangular tube | V = (W x H - (W - 2 x t) x (H - 2 x t)) x L |
Lengths in inches give in³; lengths in mm give mm³ (divide by 1,000 for cm³). lb/in³ = g/cm³ x 0.036127; 1 lb = 0.45359 kg.
| Material | Density (g/cm³) | Density (lb/in³) |
|---|---|---|
| Aluminum 6061 | 2.70 | 0.0975 |
| Aluminum 2024 | 2.78 | 0.1004 |
| Aluminum 7075 | 2.81 | 0.1015 |
| Carbon steel (1018, A36 class) | 7.85 | 0.2836 |
| Stainless 304 | 8.00 | 0.2890 |
| Brass C360 | 8.50 | 0.3071 |
| Titanium Ti-6Al-4V | 4.43 | 0.1600 |
| Copper C110 (C11000) | 8.91 | 0.3219 |
| Stainless 316 | 7.99 | 0.2887 |
| Gray cast iron (ASTM A48 class 20 to 40) | 7.15 | 0.2583 |
| Tool steel D2 | 7.70 | 0.2782 |
| Tool steel O1 | 7.80 | 0.2818 |
| Tool steel A2 | 7.75 | 0.2800 |
| Bearing bronze C932 (SAE 660) | 8.91 | 0.3219 |
| Aluminum bronze C954 | 7.45 | 0.2691 |
| Magnesium AZ31B | 1.77 | 0.0639 |
| Acetal homopolymer | 1.42 | 0.0513 |
| UHMW polyethylene | 0.93 | 0.0336 |
Nominal densities at room temperature. Alloy, temper and, for gray iron, the class move the real figure slightly. lb/in³ = g/cm³ x 0.036127.
Source: Machinery's Handbook (densities of metals: aluminum, carbon steel, 304, C360, Ti-6Al-4V); producer data sheets for the rest: Copper Development Association (C110, C954), Wieland Concast (C932), AK Steel (316), Penticton Foundry (gray iron), Uddeholm (D2, O1, A2), Galaxy Magnesium (AZ31B), DuPont (acetal homopolymer), Mitsubishi Chemical Group (UHMW).
Worked example: 2.000 in round 6061, 12.000 in long
Round bar, D = 2.000 in, L = 12.000 in, aluminum 6061 at 0.0975 lb/in³.
- V = 0.785398 x 4.000 x 12.000 = 37.699 in³.
- Weight = 37.699 x 0.0975 = 3.68 lb.
- In kg: 3.68 x 0.45359 = 1.67 kg.
Result: 3.68 lb (1.67 kg).
Worked example: carbon steel plate 25 x 200 x 500 mm
Plate, W = 200 mm, T = 25 mm, L = 500 mm, carbon steel at 7.85 g/cm³.
- V = 25 x 200 x 500 = 2,500,000 mm³ = 2,500 cm³.
- Weight = 2,500 x 7.85 = 19,625 g = 19.63 kg.
- In lb: 19.625 / 0.45359 = 43.27 lb.
Result: 19.63 kg (43.27 lb).
Worked example: 1.000 in hex brass, 12.000 in long
Hex bar, AF = 1.000 in, L = 12.000 in, brass C360 at 0.3071 lb/in³.
- V = 0.866025 x 1.000 x 12.000 = 10.392 in³.
- Weight = 10.392 x 0.3071 = 3.19 lb.
Result: 3.19 lb (1.45 kg).
Shop notes
- Sizes and densities are nominal. Mill tolerances, alloy and temper move the real weight a few percent.
- Hex and square bar with broken corners weigh a little less than the sharp-corner volume.
- For a metal not in the table, pick Other and enter its density from the alloy data sheet.
FAQ
How much does a 2 in aluminum round bar weigh per foot?
3.68 lb for 6061: 37.699 in³ x 0.0975 lb/in³.
What is the density of steel in lb/in³?
0.2836 lb/in³ (7.85 g/cm³) for carbon steel.
How do you find the weight of hex bar?
V = 0.866025 x AF^2 x L, then multiply by the density. A 1.000 in brass hex, 12 in long, weighs 3.19 lb.
Is aluminum one third the weight of steel?
About: 6061 at 2.70 g/cm³ is 34% of carbon steel at 7.85 g/cm³.
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