---
title: "Natural rubber — density, melting point and properties"
description: "Natural rubber has a density of 950 kg/m³ (920–1,000). Melting point, strength, conductivity, what it is used for, and whether it floats, rusts or is magnetic."
url: https://atoneplace.net/material/natural-rubber/
site: "At One Place"
---

# Natural rubber

**Density of natural rubber: 950 kg/m³ (920–1,000)**

0.95 g/cm³ · 59.3 lb/ft³

Still unbeaten for tear strength and for the ability to stretch several hundred percent and come back, which is why heavy truck and aircraft tyres use natural rubber where car tyres use synthetics. It has the opposite of normal thermal behaviour: a stretched rubber band contracts when heated, because heat randomizes the stretched-out molecules. Its weaknesses are ozone and oil — both crack or swell it — and latex protein allergy, which is what pushed surgical gloves towards nitrile.

## Properties

- **Density:** 950 kg/m³ (920–1,000) — 0.95 g/cm³
- **Tensile strength:** 20–30 MPa
- **Young's modulus:** 0.003 GPa
- **Thermal conductivity:** 0.13 W/(m·K)
- **Thermal expansion:** 220 µm/(m·K)
- **Floats in water:** Yes
- **Magnetic:** No

## What it is used for

- Truck and aircraft tyre carcasses
- Anti-vibration engine and building mounts
- Surgical gloves and elastic bands
- Conveyor belts and hoses

## 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
- natural rubber: 950 kg/m³
- Water — the float line: 1,000 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× |
| natural rubber ← | 950 kg/m³ | 0.95× |
| platinum | 21,450 kg/m³ | 21.45× |
| gold | 19,300 kg/m³ | 19.30× |
| tungsten | 19,250 kg/m³ | 19.25× |

## Does it rust?

Natural rubber contains no iron, so it cannot rust. Whether it degrades depends on the material, not on oxidation.

## Is it magnetic?

Natural rubber is not a metal and has no ferromagnetic response.

## Common questions

### What is the density of natural rubber?

950 kg/m³ (920–1,000), or 0.95 g/cm³.

### Does natural rubber float?

Yes. At 950 kg/m³ it is less dense than water's 1,000.

### Is natural rubber magnetic?

Natural rubber is not a metal and has no ferromagnetic response.

## Related pages

- [Does natural rubber float?](https://atoneplace.net/does-it-float/natural-rubber/)
- [PLA](https://atoneplace.net/material/pla/)
- [ABS](https://atoneplace.net/material/abs/)
- [Acrylic (PMMA)](https://atoneplace.net/material/acrylic/)
- [Polycarbonate](https://atoneplace.net/material/polycarbonate/)
- [Polypropylene](https://atoneplace.net/material/polypropylene/)
- [PTFE](https://atoneplace.net/material/ptfe/)
- [Rigid PVC](https://atoneplace.net/material/pvc-rigid/)
- [HDPE](https://atoneplace.net/material/hdpe/)

## Sources

- Typical range compiled from manufacturer specifications — At One Place (/about/)