Density of Lead: 11,340 kg/m³ — Shielding, Alloys, and High-Density Applications
Lead has a density of 11,340 kg/m³ (11.34 g/cm³), making it one of the most common high-density industrial metals. Its high density is not a drawback; it is the core value behind radiation shielding, ballast, ammunition, and sound-isolation applications.
Compared with steel, lead is about 44% heavier by volume and 4.2× denser than aluminum. See the density of steel and the density of aluminum for direct comparisons, while lead remains far lighter than gold and platinum. This page gives exact lead density values, alloy densities, radiation shielding calculations, and high-density applications, with calculations available in the material density calculator.
Key values
Lead Density: Key Values
kg/m³
11,340 kg/m³
Pure lead at 20°C
g/cm³
11.34 g/cm³
Standard reference value
lb/ft³
708.0 lb/ft³
U.S. engineering reference
Lead melts at just 327.5°C — the lowest melting point of any common structural metal. Liquid lead density is approximately 10,660 kg/m³ at the melting point.
Lead is 44% denser than steel (7,850 kg/m³) and 4.2× denser than aluminum (2,700 kg/m³).
Alloys
Lead Alloy Density Chart
Pure lead has low strength and creeps quickly, so engineering applications often add antimony, tin, calcium, arsenic, or other elements to improve mechanical performance. Alloying usually lowers density slightly, but lead alloys remain among the densest common alloy systems.
| Alloy | Composition | Density | Typical Use |
|---|---|---|---|
| Pure lead | 99.9%+ Pb | 11,340 kg/m³ | Radiation shielding, cable sheathing |
| Chemical lead | Pb + 0.06% Cu | 11,340 kg/m³ | Chemical plant equipment |
| Antimonial lead (hard lead) | Pb + 4–8% Sb | 10,900–11,100 kg/m³ | Battery grids, bullets |
| Antimonial lead (high Sb) | Pb + 11% Sb | 10,600 kg/m³ | Type metal, bearings |
| Calcium lead | Pb + 0.04–0.09% Ca | 11,300 kg/m³ | Maintenance-free batteries |
| Tin-lead solder (60/40) | 60% Sn + 40% Pb | 8,500 kg/m³ | Electronics soldering |
| Tin-lead solder (63/37) | 63% Sn + 37% Pb | 8,400 kg/m³ | Eutectic solder |
| Lead-tin alloy (5% Sn) | Pb + 5% Sn | 11,000 kg/m³ | Organ pipes, coating |
| Babbitt metal (lead-based) | Pb + Sn + Sb + Cu | 9,730 kg/m³ | Plain bearings |
| Lead shot | Pb + 0–3% Sb | 11,100–11,340 kg/m³ | Ammunition, fishing weights |
Tin-lead solders have significantly lower density than pure lead because tin (7,265 kg/m³) is much less dense. A 60/40 tin-lead solder at 8,500 kg/m³ is closer in density to steel than to pure lead.
Radiation shielding
Why Lead Is Used for Radiation Shielding
Radiation shielding works by placing dense material between the radiation source and the area to be protected. High-density materials are more effective shields because they pack more atoms into a given thickness, increasing the probability that incoming radiation will interact with an atom and be absorbed or scattered before passing through. For the underlying mass-per-volume concept, see what is density.
Lead is the dominant shielding material for three reasons that work together: First, its high density (11,340 kg/m³) means a given thickness of lead contains more mass — and more atoms — than the same thickness of most other materials. Second, lead's high atomic number (Z = 82) means its atoms have many electrons, which are highly effective at absorbing X-rays and gamma rays through photoelectric absorption and Compton scattering. Third, lead is inexpensive, easy to cast into complex shapes, and self-annealing at room temperature, making it practical for large-scale shielding installations.
Shielding effectiveness is often expressed using the half-value layer (HVL) — the thickness of material required to reduce radiation intensity by 50%. For lead, the HVL depends on the radiation energy:
| Radiation Energy | Lead HVL | Concrete HVL | Lead advantage |
|---|---|---|---|
| 100 keV (diagnostic X-ray) | 0.12 mm | 15 mm | 125× thinner |
| 500 keV | 4.0 mm | 35 mm | 8.8× thinner |
| 1 MeV (gamma) | 8.0 mm | 70 mm | 8.8× thinner |
| 2 MeV (gamma) | 13 mm | 110 mm | 8.5× thinner |
In medical X-ray rooms, lead-lined walls typically use 1.5–3 mm of lead sheet embedded in plasterboard. Lead aprons worn by radiographers contain 0.25–0.5 mm lead equivalent. Nuclear power plant shielding uses much thicker lead or high-density concrete. The key engineering trade-off is always between shielding effectiveness (favouring lead) and structural load (favouring concrete or polyethylene for neutron shielding).
High-density comparison
Lead Density vs Other High-Density Materials
In engineering, lead often competes with other high-density materials for ballast and shielding applications. Selection depends on density, cost, toxicity, and manufacturability.
| Material | Density (kg/m³) | vs Lead | Cost | Toxicity | Notes |
|---|---|---|---|---|---|
| Tungsten | 19,250 | 70% denser | High | Low | Lead-free alternative for shielding |
| Gold | 19,320 | 70% denser | Very high | Low | Not practical for shielding; see density of gold |
| Lead | 11,340 | — | Low | High | Standard shielding material |
| Bismuth | 9,780 | 14% lighter | Medium | Very low | Non-toxic lead substitute |
| Steel | 7,850 | 31% lighter | Low | Low | Structural shielding, less effective; see density of steel |
| Barium sulfate concrete | 3,500 | 69% lighter | Medium | Low | Heavyweight concrete shielding |
| Normal concrete | 2,400 | 79% lighter | Very low | Low | Bulk shielding, thick sections |
Tungsten is increasingly used as a lead-free alternative in applications where lead's toxicity is a concern — particularly in fishing weights, hunting ammunition, and some medical shielding applications. Bismuth is used in non-toxic shot for waterfowl hunting where lead is banned in many jurisdictions.
For broader material comparisons, open the density table.
Applications
High-Density Applications of Lead
Radiation shielding (medical and nuclear)
Lead sheet, brick, and glass are standard materials for X-ray room construction, CT scanner suites, and nuclear facility shielding. The combination of high density and high atomic number makes lead uniquely effective per unit thickness.
Lead-acid batteries
Despite being one of the oldest battery technologies, lead-acid batteries remain dominant in automotive starting, industrial UPS, and grid storage applications. Each battery contains lead plates (density 11,340 kg/m³) submerged in sulfuric acid — the high density of lead contributes to the battery's characteristic weight.
Ballast and counterweights
Lead's high density makes it ideal for ballast in sailboat keels, counterweights in elevators and cranes, and trim weights in aircraft. A lead keel can store more ballast mass in a smaller volume than any other practical material, lowering the boat's centre of gravity and improving stability.
Ammunition and fishing weights
Lead shot and bullets rely on high density for ballistic performance — denser projectiles retain velocity better over distance. Fishing sinkers use lead's density to sink quickly and hold position in current. Environmental concerns have driven partial substitution with bismuth and tungsten in regulated contexts.
Sound and vibration damping
Lead sheet is used as a sound barrier in walls, floors, and HVAC ductwork. Its high density and low stiffness (lead is very soft for a metal) combine to give it excellent sound transmission loss, particularly at low frequencies where lightweight materials perform poorly.
Calculate Lead Mass or Volume
Material Density Calculator
Select lead or any alloy and solve for mass or volume. Useful for shielding thickness calculations and ballast weight estimates.
Density of Gold
Compare lead against gold, tungsten, and platinum — the metals denser than lead — with full density values and application context.
FAQ
Frequently Asked Questions
What is the density of lead in kg/m³?
Pure lead has a density of 11,340 kg/m³ at 20°C. This makes it 44% denser than steel (7,850 kg/m³) and 4.2 times denser than aluminum (2,700 kg/m³). Lead alloys such as antimonial lead (hard lead) are slightly less dense at 10,600–11,100 kg/m³ depending on antimony content.
What is the density of lead in g/cm³?
Lead has a density of 11.34 g/cm³. For comparison, iron is 7.87 g/cm³, copper is 8.96 g/cm³, and gold is 19.32 g/cm³. Lead's density is high enough that a cube of lead 10 cm on each side weighs 11.34 kg — noticeably heavy for its size.
Why is lead used for radiation shielding?
Lead is effective for radiation shielding because of two combined properties: its high density (11,340 kg/m³) packs many atoms into a small thickness, and its high atomic number (Z = 82) means each atom has many electrons that efficiently absorb X-rays and gamma rays. For diagnostic X-rays (100 keV), only 0.12 mm of lead is needed to reduce intensity by 50%, compared to 15 mm of concrete.
Is lead denser than gold?
No. Gold (19,320 kg/m³) is significantly denser than lead (11,340 kg/m³) — about 70% denser. This density difference is one of the reasons gold is so difficult to counterfeit using lead: a gold bar replaced with lead would be noticeably lighter. Tungsten (19,250 kg/m³) is a much closer match to gold's density, which is why tungsten-core fake gold bars are a more serious concern. See density of gold for the full comparison.
What is the density of solder?
Common tin-lead solder densities depend on composition. 60/40 solder (60% tin, 40% lead) has a density of approximately 8,500 kg/m³, and eutectic 63/37 solder is about 8,400 kg/m³. These are significantly less dense than pure lead (11,340 kg/m³) because tin (7,265 kg/m³) is much lighter than lead. Lead-free solders (typically tin-silver-copper) have densities around 7,400 kg/m³.
What are lead-free alternatives with similar density?
Tungsten (19,250 kg/m³) is denser than lead and non-toxic, making it the preferred high-density lead substitute for applications where toxicity matters — including medical shielding, fishing weights, and hunting ammunition in regulated areas. Bismuth (9,780 kg/m³) is slightly less dense than lead but non-toxic, and is widely used as a lead-free shot substitute. Neither matches lead's combination of high density, low cost, and easy castability.