Comparative metal densities
Metal density table
Section titled “Metal density table”| Metal or alloy | Density (g/cm³) | Density (kg/m³) |
|---|---|---|
| Aluminum | 2.70 | 2700 |
| Aluminum alloy 1100 | 2.72 | 2720 |
| Aluminum alloy 2024-T6 | 2.77 | 2770 |
| Aluminum alloy 6061 | 2.72 | 2720 |
| Aluminum alloy 7050 | 2.80 | 2800 |
| Aluminum alloy 7178 | 2.83 | 2830 |
| Beryllium | 1.85 | 1840 |
| Aluminum bronze (3-10% Al) | 7.70 - 8.70 | 7700 - 8700 |
| Manganese bronze | 8.36 | 8359 |
| Phosphor bronze | 8.78 - 8.92 | 8780 - 8920 |
| Copper | 8.96 | 8940 |
| Cast iron | 6.80 - 7.80 | 6800 - 7800 |
| Inconel | 8.50 | 8497 |
| Brass 60/40 | 8.52 | 8520 |
| Yellow brass | 8.47 | 8470 |
| Cartridge brass (70% Cu, 30% Zn) | 8.53 | 8530 |
| Magnesium | 1.74 | 1738 |
| Molybdenum | 10.19 | 10188 |
| Monel | 8.36 - 8.84 | 8360 - 8840 |
| Nickel | 8.91 | 8908 |
| Gold | 19.32 | 19320 |
| Silver | 10.49 | 10490 |
| Platinum | 21.40 | 21400 |
| Lead | 11.34 | 11340 |
| Titanium | 4.51 | 4500 |
| Titanium Ti6Al4V Grade 5 | 4.43 - 4.51 | 4429 - 4512 |
| Tungsten | 19.60 | 19600 |
| Stainless steel | 7.48 - 8.00 | 7480 - 8000 |
| Carbon steel | 7.85 | 7850 |
| Zinc | 7.14 | 7135 |
Unit conversion note: 1 g/cm³ equals 1000 kg/m³. To convert to lb/ft³, multiply kg/m³ by 0.0624. To convert to lb/in³, multiply kg/m³ by 0.000036127. The reference temperature for density values is near room temperature (20 °C), unless otherwise stated.
Key performance points
Section titled “Key performance points”The density of commercial metals spans a range greater than one order of magnitude, from 1.74 g/cm³ for magnesium to 21.40 g/cm³ for platinum. The lightest structural metals —magnesium, aluminum and titanium— have densities between 1.74 and 4.51 g/cm³, making them suitable for aerospace and transportation applications where strength-to-weight ratio is critical.
Medium density metals, such as steel (7.85 g/cm³), copper (8.96 g/cm³) and nickel (8.91 g/cm³), form the backbone of construction, industrial machinery and electrical infrastructure. Copper-based alloys, such as bronzes and brasses, fall in the range of 7.70 to 8.92 g/cm³, combining moderate density with excellent corrosion resistance and conductivity.
At the upper end of the scale, dense metals find application in radiation shielding, counterweights and armor-piercing ammunition. Tungsten, at 19.60 g/cm³, and lead, at 11.34 g/cm³, are the most widely used industrially due to their relatively low cost. Precious metals such as gold (19.32 g/cm³) and platinum (21.40 g/cm³) exhibit the highest densities among metals in common use.
The density of an alloy can differ significantly from that of its base metals, requiring consideration of the chemical composition and manufacturing process. For example, commercially pure titanium has a density of 4.51 g/cm³, while the Ti6Al4V Grade 5 alloy ranges between 4.43 and 4.51 g/cm³ depending on the heat treatment.
Reference physical and mechanical properties
Section titled “Reference physical and mechanical properties”Physical and mechanical properties vary considerably among metal families and are indirectly correlated with density. The following table presents reference values for the Ti6Al4V Grade 5 alloy, representative of a high-performance light alloy, as an example of property integration:
| Property | Minimum value (SI) | Maximum value (SI) | Unit (SI) | Minimum value (Imperial) | Maximum value (Imperial) | Unit (Imperial) |
|---|---|---|---|---|---|---|
| Density | 4.429 | 4.512 | g/cm³ | 276.5 | 281.7 | lb/ft³ |
| Young’s modulus | 110 | 119 | GPa | 15.95 | 17.26 | 10⁶ psi |
| Tensile strength | 862 | 1200 | MPa | 125.0 | 174.0 | ksi |
| Yield strength | 786 | 910 | MPa | 114.0 | 132.0 | ksi |
| Compressive strength | 848 | 1080 | MPa | 123.0 | 156.6 | ksi |
| Hardness | 3370 | 3730 | MPa | 488.8 | 541.0 | ksi |
| Shear modulus | 40 | 45 | GPa | 5.80 | 6.53 | 10⁶ psi |
| Poisson’s ratio | 0.31 | 0.37 | — | 0.31 | 0.37 | — |
| Fracture toughness | 84 | 107 | MPa·m½ | 76.4 | 97.4 | ksi·in½ |
| Ductility | 0.05 | 0.18 | — | 0.05 | 0.18 | — |
| Fatigue limit | 529 | 566 | MPa | 76.7 | 82.1 | ksi |
| Melting point | 1878 | 1933 | K | 2921 | 3019 | °F |
| Thermal conductivity | 7.1 | 7.3 | W/m·K | 4.11 | 4.22 | BTU·ft/h·ft²·°F |
| Thermal expansion | 8.7 | 9.1 | 10⁻⁶/K | 15.66 | 16.38 | 10⁻⁶/°F |
| Specific heat | 553 | 570 | J/kg·K | 0.428 | 0.441 | BTU/lb·°F |
| Electrical resistivity | 168 | 170 | 10⁻⁸ Ω·m | 168 | 170 | 10⁻⁸ Ω·m |
The corrosion resistance of the Ti6Al4V Grade 5 alloy is excellent, with a rating of 5 (scale 1-5) for fresh water, seawater, organic solvents, weak acids, weak alkalis and UV radiation. It has a rating of 4 for strong acids, strong alkalis and oxidation at 500 °C. Wear resistance is moderate, with a rating of 3.
Industrial applications by density class
Section titled “Industrial applications by density class”| Metal class | Density range (g/cm³) | Representative metals | Main applications |
|---|---|---|---|
| Light metals | 1.74 – 4.51 | Magnesium, Aluminum, Titanium | Aerospace, automotive, medical devices, sporting equipment |
| Medium density metals | 7.14 – 8.96 | Steel, Copper, Nickel, Zinc, Brass | Construction, machinery, electrical conductors, piping |
| Heavy metals | 10.49 – 13.31 | Silver, Lead, Palladium, Hafnium | Radiation shielding, counterweights, batteries, electrical contacts |
| Very high density metals | 19.32 – 21.40 | Gold, Tungsten, Platinum | Armor-piercing ammunition, aircraft balancing, jewelry, crucibles |
The selection of a metal for a specific application requires balancing density with other properties such as mechanical strength, elastic modulus, corrosion resistance and, notably, cost. Aluminum, with a density of 2.70 g/cm³, dominates the transportation sector due to its combination of low weight, reasonable strength and moderate cost. Titanium, at 4.51 g/cm³, offers tensile strength comparable to many steels with 43% less weight, although its cost limits its use to high-value-added applications.
For ionizing radiation shielding, lead (11.34 g/cm³) is the most widespread option in medical and industrial environments because of its high density, low cost and ease of forming. In applications requiring higher density and a higher melting point, such as high-performance electrical contacts, tungsten (19.60 g/cm³) is the reference material.
Comparison with similar materials
Section titled “Comparison with similar materials”Within the same base metal family, density can vary appreciably depending on the alloying elements and manufacturing process. For aluminum alloys, density ranges from 2.64 g/cm³ for casting alloy 360 to 2.83 g/cm³ for high-strength alloy 7178. The addition of copper, zinc and magnesium as alloying elements tends to increase the density relative to pure aluminum (2.70 g/cm³), although in all cases it remains below 2.85 g/cm³.
Stainless steels have a density range between 7.48 and 8.00 g/cm³, with austenitic grades (such as 304 and 316) slightly denser than ferritic grades due to their higher nickel and chromium content. Carbon steel, at 7.85 g/cm³, lies in the middle of this interval.
Among bronzes, density varies significantly according to tin and aluminum content. Aluminum bronzes with low aluminum content are around 7.70 g/cm³, while phosphor bronzes reach up to 8.92 g/cm³, close to the density of pure copper (8.96 g/cm³). Brass 60/40 (8.52 g/cm³) and cartridge brass (8.53 g/cm³) have very similar densities, reflecting their predominantly copper composition with zinc as the main alloying element.
Nickel-based superalloys, such as Inconel (8.50 g/cm³), have a lower density than pure nickel (8.91 g/cm³) due to the presence of elements such as chromium and iron in their composition, which is advantageous in high-temperature aerospace applications.
Frequently Asked Questions (FAQ)
Section titled “Frequently Asked Questions (FAQ)”What is the industrial metal with the highest density?
Section titled “What is the industrial metal with the highest density?”Tungsten, with a density of 19.60 g/cm³, is the metal with the highest density used industrially, followed by gold at 19.32 g/cm³. Osmium (22.61 g/cm³) and iridium (22.65 g/cm³) have higher densities but their scarcity and cost drastically limit their applications, restricting them to special very high hardness alloys. In radiation shielding applications where weight is a functional factor, lead (11.34 g/cm³) remains the predominant choice due to its cost-density ratio.
What is the weight difference between an aluminum part and an equivalent steel part?
Section titled “What is the weight difference between an aluminum part and an equivalent steel part?”An aluminum part weighs approximately 65% less than a geometrically identical part made of carbon steel (density 7.85 g/cm³ vs. 2.70 g/cm³). This difference has driven the progressive replacement of steel by aluminum in automotive bodies, aerospace structures and transportation components, achieving mass reductions of up to two-thirds without modifying the volumetric design of the component.
What is the density of titanium alloy Ti6Al4V Grade 5?
Section titled “What is the density of titanium alloy Ti6Al4V Grade 5?”The density of Ti6Al4V Grade 5 alloy is in the range of 4.43 to 4.51 g/cm³, equivalent to a value between 277 and 282 lb/ft³. This density is approximately 43% lower than that of steel and 60% higher than that of aluminum, placing titanium as the material of choice when the maximum strength-to-weight ratio is required in high-performance structural applications.
In what density range do stainless steels fall?
Section titled “In what density range do stainless steels fall?”Stainless steels have densities between 7.48 and 8.00 g/cm³, varying according to their microstructure: ferritic grades tend toward the lower end of the range, while austenitic grades, with higher nickel and chromium content, reach the upper values. This variation, although moderate in percentage terms, can be relevant in the design of large structures or components subject to strict mass requirements.
How are density units converted between the metric and imperial systems?
Section titled “How are density units converted between the metric and imperial systems?”The fundamental conversion factor is 1 kg/m³ = 0.0624 lb/ft³. To convert g/cm³ to kg/m³ simply multiply by 1000, so 8.96 g/cm³ equals 8960 kg/m³ or 559 lb/ft³. In the reverse direction, a density expressed in lb/ft³ is converted to kg/m³ by multiplying by 16.018. The relationship with lb/in³ is 1 kg/m³ = 0.000036127 lb/in³, so 7850 kg/m³ equals 0.284 lb/in³.
What is the lightest structural metal commercially available?
Section titled “What is the lightest structural metal commercially available?”Magnesium, with a density of 1.74 g/cm³, is the lightest structural metal in commercial use, followed by beryllium at 1.85 g/cm³. Magnesium alloys such as AZ31B (1.77 g/cm³) are used in electronic device housings, automotive components and aerospace structures where each gram of reduction is critical. The main limiting factor for its adoption is its lower corrosion resistance compared to aluminum.
Sources
Section titled “Sources”- azom.com: https://www.azom.com/properties.aspx?ArticleID=1547
- engineeringtoolbox.com: https://www.engineeringtoolbox.com/metal-alloys-densities-d_50.html
References
Section titled “References”- azom.com: https://www.azom.com/properties.aspx?ArticleID=1547
- engineeringtoolbox.com: https://www.engineeringtoolbox.com/metal-alloys-densities-d_50.html