---
title: "Copper — density, melting point and properties"
description: "Copper has a density of 8,960 kg/m³. Melting point, strength, conductivity, what it is used for, and whether it floats, rusts or is magnetic."
url: https://atoneplace.net/material/copper/
site: "At One Place"
---

# Copper

**Density of copper: 8,960 kg/m³**

8.96 g/cm³ · 559.4 lb/ft³

Second only to silver in electrical and thermal conductivity, and silver costs roughly a hundred times more per kilogram, which settles the argument for almost every application. Slightly denser than steel, so a copper pipe feels surprisingly heavy for its size. The 210-360 MPa span is annealed to hard-drawn: the same wire doubles in strength purely from being pulled through a die, and softens again if you anneal it.

## Properties

- **Density:** 8,960 kg/m³ — 8.96 g/cm³
- **Melting point:** 1,084.6 °C
- **Tensile strength:** 210–360 MPa
- **Young's modulus:** 117 GPa
- **Thermal conductivity:** 401 W/(m·K)
- **Thermal expansion:** 16.5 µm/(m·K)
- **Floats in water:** No
- **Magnetic:** No

## What it is used for

- Electrical wiring and busbars
- Domestic water and heating pipe
- Motor and transformer windings
- Roofing and rainwater goods

## How it compares

*Water is 1,000 kg/m³. Anything with a shorter bar than water floats in it.*

- air: 1.2 kg/m³
- expanded polystyrene foam: 20 kg/m³
- rigid polyurethane foam: 40 kg/m³
- Water — the float line: 1,000 kg/m³
- copper: 8,960 kg/m³
- tungsten: 19,250 kg/m³
- gold: 19,300 kg/m³
- platinum: 21,450 kg/m³

*Water is 1,000 kg/m³. Anything below that floats.*

| Material | Density | Relative to water |
| --- | --- | --- |
| rigid polyurethane foam | 40 kg/m³ | 0.04× |
| expanded polystyrene foam | 20 kg/m³ | 0.02× |
| air | 1.2 kg/m³ | 0.00× |
| copper ← | 8,960 kg/m³ | 8.96× |
| platinum | 21,450 kg/m³ | 21.45× |
| gold | 19,300 kg/m³ | 19.30× |
| tungsten | 19,250 kg/m³ | 19.25× |

## Does it rust?

No. Copper and its alloys cannot rust, since rust is iron oxide. They form a patina instead — copper oxide first, turning to the familiar green carbonate over decades — and that layer is adherent and protective, which is why copper roofs last centuries.

## Is it magnetic?

Copper is not ferromagnetic. It is often assumed to be because it is a metal, but most metals are not — only iron, nickel, cobalt and a few alloys are attracted to an ordinary magnet.

## Common questions

### What is the density of copper?

8,960 kg/m³, or 8.96 g/cm³.

### Does copper float?

No. At 8,960 kg/m³ it is denser than water.

### Is copper magnetic?

Copper is not ferromagnetic. It is often assumed to be because it is a metal, but most metals are not — only iron, nickel, cobalt and a few alloys are attracted to an ordinary magnet.

## Related pages

- [Does copper float?](https://atoneplace.net/does-it-float/copper/)
- [Aluminum](https://atoneplace.net/material/aluminum/)
- [Gold](https://atoneplace.net/material/gold/)
- [Titanium](https://atoneplace.net/material/titanium/)
- [Iron](https://atoneplace.net/material/iron/)
- [Lead](https://atoneplace.net/material/lead/)
- [Tungsten](https://atoneplace.net/material/tungsten/)
- [Silver](https://atoneplace.net/material/silver/)
- [Mercury](https://atoneplace.net/material/mercury/)

## Sources

- Wikidata — Wikimedia Foundation (https://www.wikidata.org/) [CC0 1.0]